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  • 1.
    Abd Alrahman, Chadi
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Khodabakhsh, Amir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Schmidt, Florian M.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Qu, Zhechao
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Cavity-enhanced optical frequency comb spectroscopy of high-temperature H2O in a flame2014In: Optics Express, E-ISSN 1094-4087, Vol. 22, no 11, p. 13889-13895Article in journal (Refereed)
    Abstract [en]

    We demonstrate near-infrared cavity-enhanced optical frequency comb spectroscopy of water in a premixed methane/air flat flame. The detection system is based on an Er:fiber femtosecond laser, a high finesse optical cavity containing the flame, and a fast-scanning Fourier transform spectrometer (FTS). High absorption sensitivity is obtained by the combination of a high-bandwidth two-point comb-cavity lock and auto-balanced detection in the FTS. The system allows recording high-temperature water absorption spectra with a resolution of 1 GHz and a bandwidth of 50 nm in an acquisition time of 0.4 s, with absorption sensitivity of 4.2 x 10 (9) cm(-1) Hz(-1/2) per spectral element.

  • 2.
    Axner, Ove
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ehlers, Patrick
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wang, Junyang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    NICE-OHMS – frequency modulation cavity-enhanced spectroscopy: principles and performance2014In: Cavity-Enhanced Spectroscopy and Sensing / [ed] Gianluca Gagliardi and Hans-Peter Loock, Berlin: Springer Berlin/Heidelberg, 2014, p. 221-251Chapter in book (Refereed)
    Abstract [en]

    Noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is a sensitive technique for detection of molecular species in gas phase. It is based on a combination of frequency modulation for reduction of noise and cavity enhancement for prolongation of the interaction length between the light and a sample. It is capable of both Doppler-broadened and sub-Doppler detection with absorption sensitivity down to the 10−12 and 10−14 Hz−1/2 cm−1 range, respectively. This chapter provides a thorough description of the basic principles and the performance of the technique.

  • 3.
    Axner, Ove
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ehlers, Patrick
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz-Matyba, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wang, Junyang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    NICE-OHMS – Frequency modulation cavity-enhanced spectroscopy: principles and performanceManuscript (preprint) (Other academic)
  • 4.
    Axner, Ove
    et al.
    Umeå University, Faculty of Science and Technology, Physics.
    Ma, Weiguang
    Umeå University, Faculty of Science and Technology, Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Physics. Umeå University, Faculty of Science and Technology, Physics.
    Sub-Doppler dispersion and noise-immune cavity-enhanced optical heterodyne molecular spectroscopy revised2008In: Journal of the Optical Society of America B, Vol. 25, no 7, p. 1166-1177Article in journal (Refereed)
    Abstract [en]

    An expression for the peak-to-peak sub-Doppler optical phase shift of two counter-propagating modes of light, to which the noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) dispersion signal is proportional, valid for arbitrary degree of saturation, is derived.

    For low degrees of saturation it agrees with the expression for weakly saturating (ws) conditions, [(1+S)-1/2-(1+2S)-1/20/2, where S is the degree of saturation and α0 the unsaturated peak absorption.

    However, the new expression, which can be written as 0.45S(1+S)-1α0/2, does not predict a distinct maximum as the ws-expression does; instead it predicts an optical phase shift that increases monotonically with S and levels off to 0.45α0/2 for large S. This alters the optimum conditions for the sub-Doppler NICE-OHMS technique and improves its shot-noise-limited detectability.

    The new expression is based upon the same explicit assumptions as the ws-expression but not the Kramers-Kronig’s relations, which are not valid for nonlinear responses, and is supported by experimental results up to S = 100. The new expression is expected to be valid for all techniques measuring sub-Doppler dispersion signals

  • 5.
    Axner, Ove
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Schmidt, Florian M.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Gustafsson, Jörgen
    Omenetto, Nicoló
    Winefordner, James D.
    Absorption spectrometry by narrowband light in optically saturated and optically pumped collision and doppler broadened gaseous media under arbitrary optical thickness conditions2006In: Applied Spectroscopy, ISSN 0003-7028, E-ISSN 1943-3530, Vol. 60, no 11, p. 1217-1240Article in journal (Refereed)
    Abstract [en]

    This work examines absorption spectrometry by narrowband light in gaseous media with arbitrary optical thickness when the light induces optical saturation or optical pumping. Two quantities are defined: the observed absorbance, Aobs, and the true absorbance, Atrue. The former is the absorbance that is measured under the existing conditions, whereas the latter represents the absorbance one would measure if the light acted solely as a probe of the populations of the various levels, and it is therefore directly proportional to the concentration or density of absorbers. A general integral equation for the propagation of light in media of arbitrary optical thickness in which the light influences the populations of the levels involved is derived. This expression is transcendental in the observed absorbance and cannot be solved analytically. It is shown that an analytical expression can be derived by investigating the inverse relationship, i.e., Atruef(Aobs). Inasmuch as collision and Doppler broadened media react differently to optical saturation, they are considered separately. It is shown that a nonlinear response results if the medium is optically saturated (or pumped) and not optically thin. Expressions for the error introduced if the technique of standard additions is uncritically applied to such a system are derived.

  • 6.
    Ehlers, Patrick
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Johansson, Alexandra C
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Use of etalon-immune distances to reduce the influence of background signals in frequency-modulation spectroscopy and noise-immune cavity-enhanced optical heterodyne molecular spectroscopy2014In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 31, no 12, p. 2938-2945Article in journal (Refereed)
    Abstract [en]

    The detection sensitivity of phase-modulated techniques such as frequency-modulation spectroscopy (FMS) and noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is often limited by etalon background signals. It has previously been shown that the impact of etalons can be reduced by the use of etalon-immune distances (EIDs), i.e., by separating the surfaces that give rise to etalons by a distance of q. L-m, where L-m is given by c/2n nu(m), where, in turn, n and nu(m) are the index of refraction between the components that make up the etalon (thus most often that of air) and the modulation frequency, respectively, and where q is an integer (i.e., 1, 2, 3,.) or half-integer (i.e., 1/2, 1, 3/2,.) for the dispersion and absorption modes of detection, respectively. An etalon created by surfaces separated by an EID will evade detection and thereby not contribute to any background signal. The concept of EIDs in FMS and NICE-OHMS is in this work demonstrated, scrutinized, and discussed in some detail. It is shown that the influence of EIDs on the absorption and dispersion modes of detection is significantly different; signals detected at the dispersion phase are considerably less sensitive to deviations from exact EID conditions than those detected at the absorption phase. For example, the FM background signal from an etalon whose length deviates from an EID by 2.5% of L-m (e.g., by 1 cm for an L-m of 40 cm), detected in dispersion, is only 9% of that in absorption. This makes the former mode of detection the preferred one whenever a sturdy immunity against etalons is needed or when optical components with parallel surfaces (e.g., lenses, polarizers, or beam splitters) are used. The impact of the concept of EIDs on NICE-OHMS is demonstrated by the use of Allan-Werle plots.

  • 7.
    Ehlers, Patrick
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wang, Junyang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Fiber-laser-based noise-immune cavity-enhanced optical heterodyne molecular spectrometry incorporating an optical circulator2014In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 39, no 2, p. 279-282Article in journal (Refereed)
    Abstract [en]

    To reduce the complexity of fiber-laser-based noise-immune cavity-enhanced optical heterodyne molecular spectrometry, a system incorporating a fiber-coupled optical circulator to deflect the cavity-reflected light for laser stabilization has been realized. Detection near the shot-noise limit has been demonstrated for both Doppler-broadened and sub-Doppler signals, yielding a lowest detectable absorption and optical phase shift of 2.2 x 10(-12) cm(-1) and 4.0 x 10(-12) cm(-1), respectively, both for a 10 s integration time, where the former corresponds to a detection limit of C2H2 of 5 ppt. (C) 2014 Optical Society of America

  • 8.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Fiber-laser-based noise-immune cavity-enhanced optical heterodyne molecular spectrometry2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Noise-immune cavity-enhanced optical heterodyne molecular spectro-metry (NICE-OHMS) is one of the most sensitive laser-based absorption techniques. The high sensitivity of NICE-OHMS is obtained by a unique combination of cavity enhancement (for increased interaction length with a sample) with frequency modulation spectrometry (for reduction of noise). Moreover, sub-Doppler detection is possible due to the presence of high intensity counter-propagating waves inside an external resonator, which provides an excellent spectral selectivity. The high sensitivity and selectivity make NICE-OHMS particularly suitable for trace gas detection. Despite this, the technique has so far not been often used for practical applications due to its technical complexity, originating primarily from the requirement of an active stabilization of the laser frequency to a cavity mode.

    The main aim of the work presented in this thesis has been to develop a simpler and more robust NICE-OHMS instrumentation without compro-mising the high sensitivity and selectivity of the technique. A compact NICE-OHMS setup based on a fiber laser and a fiber-coupled electro-optic modulator has been constructed. The main advantage of the fiber laser is its narrow free-running linewidth, which significantly simplifies the frequency stabilization procedure. It has been demonstrated, using acetylene and carbon dioxide as pilot species, that the system is capable of detecting relative absorption down to 3 × 10-9 on a Doppler-broadened transition, and sub-Doppler optical phase shift down to 1.6 × 10-10, the latter corresponding to a detection limit of 1 × 10-12 atm of C2H2. Moreover, the potential of dual frequency modulation dispersion spectrometry (DFM-DS), an integral part of NICE-OHMS, for concentration measurements has been assessed.

    This thesis contributes also to the theoretical description of Doppler-broadened and sub-Doppler NICE-OHMS signals, as well as DFM-DS signals. It has been shown that the concentration of an analyte can be deduced from a Doppler-broadened NICE-OHMS signal detected at an arbitrary and unknown detection phase, provided that a fit of the theoretical lineshape to the experimental data is performed. The influence of optical saturation on Doppler-broadened NICE-OHMS signals has been described theoretically and demonstrated experimentally. In particular, it has been shown that the Doppler-broadened dispersion signal is unaffected by optical saturation in the Doppler limit. An expression for the sub-Doppler optical phase shift, valid for high degrees of saturation, has been derived and verified experimentally up to degrees of saturation of 100.

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  • 9.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Khodabakhsh, Amir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Abd Alrahman, Chadi
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Johansson, Alexandra C.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Broadband molecular detection with cavity-enhanced optical frequency comb spectroscopy2014In: Optical instrumentation for energy and environmental applications, E2 2014, Optical Society of America (OSA) , 2014, article id EW4A.3Conference paper (Refereed)
    Abstract [en]

    We demonstrate detection of atmospheric species in air and combustion environment using near-infrared cavity-enhanced optical frequency comb spectroscopy based on an Er:fiber femtosecond laser and a fast-scanning Fourier transform spectrometer.

  • 10.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Khodabakhsh, Amir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Johansson, Alexandra C.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ramaiah-Badarla, Venkata
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Cavity-enhanced optical frequency combs spectroscopy in the near- and mid-infrared2016In: Imaging and applied optics 2016: proceedings, OSA - The Optical Society , 2016, article id LT1G.1Conference paper (Refereed)
    Abstract [en]

    We present the recent developments in high-resolution Fourier transform spectroscopy based on optical frequency combs for precision measurements and combustion diagnostics, and the first implementation of continuous-filtering Vernier spectroscopy in the mid-infrared wavelength range for fast multispecies detection.

  • 11.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ma, Weiguang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Characterization of fiber-laser-based sub-Doppler NICE-OHMS for quantitative trace gas detection2008In: Optics Express, E-ISSN 1094-4087, Vol. 16, no 19, p. 14689-14702Article in journal (Refereed)
    Abstract [en]

    The potential of fiber-laser-based sub-Doppler noise-immune cavity-enhanced optical heterodyne molecular spectrometry for trace gas detection is scrutinized. The non-linear dependence of the on-resonance sub-Doppler dispersion signal on the intracavity pressure and power is investigated and the optimum conditions with respect to these are determined. The linearity of the signal strength with concentration is demonstrated and the dynamic range of the technique is discussed. Measurements were performed on C2H2 at 1531 nm up to degrees of saturation of 100. The minimum detectable sub-Doppler optical phase shift was 5 x 10-11 cm-1 Hz-1/2, corresponding to a partial pressure of C2H2 of 1 x 10-12 atm for an intracavity pressure of 20 mTorr, and a concentration of 10 ppb at 400 mTorr.

  • 12.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ma, Weiguang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Schmidt, Florian M.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Doppler-broadened noise-immune cavity-enhanced optical heterodyne molecular spectrometry signals from optically saturated transitions under low pressure conditions2008In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 25, no 7, p. 1156-1165Article in journal (Refereed)
    Abstract [en]

    The influence of optical saturation on noise-immune cavity-enhanced optical heterodyne molecular spectrometry (NICE-OHMS) signals from purely Doppler-broadened transitions is investigated experimentally. It is shown that the shape and the strength of the dispersion signal are virtually unaffected by optical saturation, whereas the strength of the absorption signal decreases as (1+G+-1)-1/2, where G+-1 is the degree of saturation induced by the sideband of the frequency modulated triplet, in agreement with theoretical predictions. This implies, first of all, that Doppler-broadened NICE-OHMS is affected less by optical saturation than other cavity enhanced techniques but also that it exhibits nonlinearities in the power and pressure dependence for all detection phases except pure dispersion. A methodology for assessments of the degree of saturation and the saturation power of a transition from Doppler-broadened NICE-OHMS signals is given. The implications of optical saturation for practical trace species detection by Doppler-broadened NICE-OHMS are discussed.

  • 13.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ma, Weiguang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Schmidt, Florian M
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wavelength modulated noise-immune cavity-enhanced optical heterodyne molecular spectroscopy signal line shapes in the Doppler limit2009In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 26, no 7, p. 1384-1394Article in journal (Refereed)
    Abstract [en]

    A thorough analysis of the shape and strength of Doppler-broadened wavelength modulated noise-immune cavity-enhanced optical heterodyne molecular spectroscopy signals is presented and their dependence on modulation frequency, modulation amplitude and detection phase is investigated in detail. The conditions that maximize the on-resonance signal are identified. The analysis is based on the standard frequency modulation spectroscopy formalism and the Fourier description of wavelength modulation spectroscopy and verified by fits to experimental signals from C2H2 and CO2 measured at 1531 nm. In addition, the line strengths of two CO2 transitions in the v2→3v1+v2+v3 hot band [Pe(7) and Pe(9)] were found to differ by ~20% from those given in the HITRAN database.

  • 14.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics. JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, USA.
    Maslowski, P.
    JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, Boulder, CO, 80309-0440, USA and Instytut Fizyki, Uniwersytet Mikołaja Kopernika, Torun, Poland.
    Fleisher, A. J.
    JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, Boulder, CO, 80309-0440, USA.
    Bjork, B. J.
    JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, Boulder, CO, 80309-0440, USA.
    Ye, J.
    JILA, National Institute of Standards and Technology and University of Colorado, Department of Physics, University of Colorado, Boulder, CO, 80309-0440, USA.
    Cavity-enhanced optical frequency comb spectroscopy in the mid-infrared application to trace detection of hydrogen peroxide2013In: Applied physics. B, Lasers and optics (Print), ISSN 0946-2171, E-ISSN 1432-0649, Vol. 110, no 2, p. 163-175Article in journal (Refereed)
    Abstract [en]

    We demonstrate the first cavity-enhanced optical frequency comb spectroscopy in the mid-infrared wavelength region and report the sensitive real-time trace detection of hydrogen peroxide in the presence of a large amount of water. The experimental apparatus is based on a mid-infrared optical parametric oscillator synchronously pumped by a high-power Yb:fiber laser, a high-finesse broadband cavity, and a fast-scanning Fourier transform spectrometer with autobalancing detection. The comb spectrum with a bandwidth of 200 nm centered around 3.76 μm is simultaneously coupled to the cavity and both degrees of freedom of the comb, i.e. the repetition rate and carrier envelope offset frequency, are locked to the cavity to ensure stable transmission. The autobalancing detection scheme reduces the intensity noise by a factor of 300, and a sensitivity of 5.4×10-9 cm-1 Hz-1/2 with a resolution of 800 MHz is achieved (corresponding to 6.9×10-11 cm-1 Hz-1/2 per spectral element for 6000 resolved elements). This yields a noise equivalent detection limit for hydrogen peroxide of 8 parts-per-billion (ppb); in the presence of 2.8 % of water the detection limit is 130 ppb. Spectra of acetylene, methane, and nitrous oxide at atmospheric pressure are also presented, and a line-shape model is developed to simulate the experimental data.

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  • 15.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Université de Rennes, CNRS, IPR (Institut de Physique de Rennes), UMR 6251, Rennes, France.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Johansson, Alexandra C.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silva de Oliveira, Vinicius
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Soboń, Grzegorz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Martynkien, Tadeusz
    Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wroclaw, Poland.
    Mergo, Paweł
    Laboratory of Optical Fiber Technology, Maria Curie-Sklodowska University, Lublin, Poland.
    Lehmann, Kevin K.
    Departments of Chemistry and Physics, University of Virginia, VA, Charlottesville, United States.
    Measurement and assignment of double-resonance transitions to the 8900-9100- cm-1 levels of methane2021In: Physical Review A: covering atomic, molecular, and optical physics and quantum information, ISSN 2469-9926, E-ISSN 2469-9934, Vol. 103, no 2, article id 022810Article in journal (Refereed)
    Abstract [en]

    Optical-optical double-resonance spectroscopy with a continuous wave pump and frequency comb probe allows measurement of sub-Doppler transitions to highly excited molecular states over a wide spectral range with high frequency accuracy. We report on assessment and characterization of sub-Doppler double-resonance transitions in methane measured using a 3.3-μm continuous wave optical parametric oscillator as a pump and a 1.67-μm frequency comb as a probe. The comb spectra were recorded using a Fourier transform spectrometer with comb-mode-limited resolution. With the pump tuned to nine different transitions in the ν3 fundamental band, we detected 36 ladder-type transitions to the 3ν3 overtone band region, and 18 V-type transitions to the 2ν3 overtone band. We describe in detail the experimental approach and the pump stabilization scheme, which currently limits the frequency accuracy of the measurement. We present the data analysis procedure used to extract the frequencies and intensities of the probe transitions for parallel and perpendicular relative pump-probe polarization. We compare the center frequencies and relative intensities of the ladder-type transitions to theoretical predictions from the TheoReTS and ExoMol line lists, demonstrating good agreement with TheoReTS.

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  • 16.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Université de Rennes, CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, Rennes, France.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Johansson, Alexandra C.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silva de Oliveira, Vinicius
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Soboń, Grzegorz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Martynkien, Tadeusz
    Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wroclaw, Poland.
    Mergo, Paweł
    Laboratory of Optical Fiber Technology, Maria Curie-Sklodowska University, Lublin, Poland.
    Lehmann, Kevin K.
    Departments of Chemistry and Physics, University of Virginia, VA, Charlottesville, United States.
    Sub-Doppler Double-Resonance Spectroscopy of Methane Using a Frequency Comb Probe2021In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 126, no 6, article id 063001Article in journal (Refereed)
    Abstract [en]

    We report the first measurement of sub-Doppler molecular response using a frequency comb by employing the comb as a probe in optical-optical double-resonance spectroscopy. We use a 3.3 μm continuous wave pump and a 1.67 μm comb probe to detect sub-Doppler transitions to the 2ν3 and 3ν3 bands of methane with ∼1.7 MHz center frequency accuracy. These measurements provide the first verification of the accuracy of theoretical predictions from highly vibrationally excited states, needed to model the high-temperature spectra of exoplanets. Transition frequencies to the 3ν3 band show good agreement with the TheoReTS line list.

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  • 17.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Univ Rennes, CNRS, IPR (Institut de Physique de Rennes), UMR 6251, Rennes, France.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Johansson, Alexandra C.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silva de Oliveira, Vinicius
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Soboń, Grzegorz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Martynkien, Tadeusz
    Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, Wroclaw, Poland.
    Mergo, Paweł
    Laboratory of Optical Fiber Technology, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 3, Lublin, Poland.
    Lehmann, Kevin K.
    Departments of Chemistry and Physics, University of Virginia, VA, Charlottesville, United States.
    Sub-doppler double-resonance spectroscopy of methane using a frequency comb probe2020In: Conference on Lasers and Electro-Optics, Optica Publishing Group (formerly OSA) , 2020, article id STu4N.1Conference paper (Refereed)
    Abstract [en]

    We use a 3.3 µm continuous wave optical parametric oscillator as a pump and a 1.67 µm frequency comb as a probe to record 36 sub-Doppler double-resonance transitions in the 3v3 band of methane (including 26 previously unreported) with ~1.5 MHz center frequency accuracy.

  • 18.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Univ Rennes, Cnrs, Ipr Institut de Physique de Rennes-UMR 6251, Rennes, France.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Johansson, Alexandra C.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silva de Oliveira, Vinicius
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Soboń, Grzegorz
    Laser AND Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Martynkien, Tadeusz
    Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Mergo, Paweł
    Laboratory of Optical Fiber Technology, Maria Curie-Sklodowska University, pl. M. Curie-Sklodowskiej 3, Lublin, Poland.
    Lehmann, Kevin K.
    Departments of Chemistry AND Physics, University of Virginia, VA, Charlottesville, United States.
    Sub-doppler double-resonance spectroscopy of methane using a frequency comb probe2020In: 2020 conference on lasers and electro-optics (CLEO): proceedings, IEEE conference proceedings, 2020, article id 9192344Conference paper (Refereed)
    Abstract [en]

    We use a 3.3 μm continuous wave optical parametric oscillator as a pump and a 1.67 μm frequency comb as a probe to record 36 sub-Doppler double-resonance transitions in the 3v3 band of methane (including 26 previously unreported) with ∼1.5 MHz center frequency accuracy.

  • 19.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Schmidt, Florian M.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Gustafsson, Jörgen
    School of Engineering, Jönköping University, Jönköping, Sweden.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wavelength modulation absorption spectrometry from optically pumped collision broadened atoms and molecules2007In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 108, no 2, p. 220-238Article in journal (Refereed)
    Abstract [en]

    A theoretical investigation of the influence of optical pumping on wavelength modulation absorption spectrometry (WMAS) signals from collision broadened atoms and molecules is presented. General expressions for the nf-WMAS signal from atomic and molecular systems, modeled as three-level systems that can accommodate both optical saturation and optical pumping, are derived by the use of a previously developed Fourier series-based formalism in combination with rate equations solved under steady-state conditions. The expressions are similar to those describing the nf-WMAS signal from two-level systems that can accommodate optical saturation [Schmidt FM, Foltynowicz A, Gustafsson J, Axner O, WMAS from optically saturated collision-broadened transitions. JQSRT 2005;94:225–54], the difference being the value of the saturation flux, wherefore the general parametric dependence of WMAS signals from optically pumped systems is the same as that from optically saturated systems. The additional effect of optical pumping on the WMAS signal is investigated for three typical cases: molecules or atoms in an ordinary atmosphere, atoms in an inert atmosphere, and atoms or molecules possessing metastable states. The possibility to describe any of these systems with a two-level model is investigated.

  • 20.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Schmidt, Florian M
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ma, Weiguang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Noise-immune cavity-enhanced optical heterodyne molecular spectrometry: Current status and future potential2008In: Applied physics. B, Lasers and optics (Print), ISSN 0946-2171, E-ISSN 1432-0649, Vol. 92, no 3, p. 313-326Article in journal (Refereed)
    Abstract [en]

    As a result of a combination of an external cavity and modulation techniques, noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is one of the most sensitive absorption techniques, capable of reaching close-to-shot-noise sensitivities, down to 5×10-13 fractional absorption at 1 s averaging. Due to its ability to provide sub-Doppler signals from weak molecular overtone transitions, the technique was first developed for frequency standard applications. It has since then also found use in fields of molecular spectroscopy of weak overtone transitions and trace gas detection. This paper describes the principles and the unique properties of NICE-OHMS. The historical background, the contributions of various groups, as well as the performance and present status of the technique are reviewed. Recent progress is highlighted and the future potential of the technique for trace species detection is discussed.

  • 21.
    Foltynowicz, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wang, Junyang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Ehlers, Patrick
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Distributed-feedback-laser-based NICE-OHMS
in the pressure-broadened regime2010In: Optics Express, E-ISSN 1094-4087, Vol. 18, no 18, p. 18580-18591Article in journal (Refereed)
    Abstract [en]

    A compact noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) system based on a narrow linewidth distributed-feedback laser and fiber-coupled acousto-optic and electro-optic modulators has been developed. Measurements of absorption and dispersion signals have been performed at pressures up to 1/3 atmosphere on weak acetylene transitions at 1551 nm. Multiline fitting routines were implemented to obtain transition parameters, i.e., center frequencies, linestrengths, and pressure broadening coefficients. The signal strength was shown to be linear with pressure and concentration, and independent of detection phase. The minimum detectable on-resonance absorption with a cavity with a finesse of 460 was 2 × 10−10 cm−1 for 1 minute of integration time.

  • 22.
    Foltynowicz-Matyba, Aleksandra
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Reduction of background signals in fiber-based NICE-OHMS2011In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 28, no 11, p. 2797-2805Article in journal (Refereed)
    Abstract [en]

    Noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) based on a fiber-coupled electro-optic modulator (EOM) provides a compact and versatile experimental setup. It has, however, been limited by background signals originating from an imbalance of the phase modulated triplet created by a cross-coupling between the principal axes of the polarization maintaining fibers and the extraordinary axis of the EOM. Two strategies for reducing these background signals are investigated: (i) using an EOM with a titanium diffused waveguide, in which the balance of the triplet is controlled by active feedback, and (ii) using an EOM with a proton exchanged waveguide that does not support light propagation along the ordinary axis. It is shown that both approaches significantly reduce drifts and noise in the system. Using a cavity with a finesse of 5700, an absorption sensitivity of 3: 2 x 10(-12) cm(-1) in 1 min of integration time (i.e., 1: 8 x 10(-11) cm(-1) Hz(-1/2)) is demonstrated for Doppler-broadened detection, the lowest reported so far for Doppler-broadened NICE-OHMS. For sub-Doppler detection, a minimum detectable optical phase shift of 1: 3 x 10(-12) cm(-1) in 400s of integration time is obtained. (C) 2011 Optical Society of America

  • 23.
    Germann, Matthias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hjältén, Adrian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Boudon, Vincent
    Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS/Université Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47870, Dijon Cedex, France.
    Richard, Cyril
    Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS/Université Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47870, Dijon Cedex, France.
    Krzempek, Karol
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland.
    Hudzikowski, Arkadiusz
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland.
    Głuszek, Aleksander
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland.
    Soboń, Grzegorz
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    A methane line list with sub-MHz accuracy in the 1250 to 1380 cm−1 range from optical frequency comb Fourier transform spectroscopy2022In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 288, article id 108252Article in journal (Refereed)
    Abstract [en]

    We use a Fourier transform spectrometer based on a difference frequency generation optical frequency comb to measure high-resolution, low-pressure, room-temperature spectra of methane in the 1250 – 1380-cm−1 range. From these spectra, we retrieve line positions and intensities of 678 lines of two isotopologues: 157 lines from the 12CH4 ν4 fundamental band, 131 lines from the 13CH4 ν4 fundamental band, as well as 390 lines from two 12CH4 hot bands, ν2 + ν4 ν2 and 2ν4ν4. For another 165 lines from the 12CH4 ν4 fundamental band we retrieve line positions only. The uncertainties of the line positions range from 0.19 to 2.3 MHz, and their median value is reduced by a factor of 18 and 59 compared to the previously available data for the 12CH4 fundamental and hot bands, respectively, obtained from conventional FTIR absorption measurements. The new line positions are included in the global models of the spectrum of both methane isotopologues, and the fit residuals are reduced by a factor of 8 compared to previous absorption data, and 20 compared to emission data. The experimental line intensities have relative uncertainties in the range of 1.5 – 7.7%, similar to those in the previously available data; 235 new 12CH4 line intensities are included in the global model.

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  • 24.
    Germann, Matthias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hjältén, Adrian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Boudon, Vincent
    Laboratoire Interdisciplinaire Carnot de Bourgogne, Université Bourgogne Franche-Comté, Dijon, France.
    Richard, Cyril
    Laboratoire Interdisciplinaire Carnot de Bourgogne, Université Bourgogne Franche-Comté, Dijon, France.
    Krzempek, Karol
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Hudzikowski, Arkadiusz
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Głuszek, Aleksander
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Soboń, Grzegorz
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    An Accurate Methane Line List in the 7.2-8.0 µm Range from Comb-Based Fourier Transform Spectroscopy2022In: CLEO: 2022: Conference on Lasers and Electro-Optics, Optica Publishing Group , 2022, article id SM3F.6Conference paper (Refereed)
    Abstract [en]

    We use comb-based Fourier transform spectroscopy to record high-resolution spectra of 12CH4 and 13CH4 from 1250 to 1380 cm-1. We obtain line positions and intensities of 4 bands with uncertainties of ~450 kHz and ~3%, respectively, which we use to improve a global fit of the effective Hamiltonian.

  • 25.
    Germann, Matthias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hjältén, Adrian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Boudon, Vincent
    Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Université Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47870, Dijon, France.
    Richard, Cyril
    Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Université Bourgogne Franche-Comté, 9 Av. A. Savary, BP 47870, Dijon, France.
    Krzempek, Karol
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland.
    Hudzikowski, Arkadiusz
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland.
    Głuszek, Aleksander
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland.
    Soboń, Grzegorz
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, Wrocław, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    An Accurate Methane Line List in the 7.2-8.0 μm Range from Comb-Based Fourier Transform Spectroscopy2022In: 2022 Conference on Lasers and Electro-Optics, CLEO 2022 - Proceedings, Optica Publishing Group , 2022, article id SM3F.6Conference paper (Refereed)
    Abstract [en]

    We use comb-based Fourier transform spectroscopy to record high-resolution spectra of 12CH4 and 13CH4 from 1250 to 1380 cm-1. We obtain line positions and intensities of 4 bands with uncertainties of ~450 kHz and ~3%, respectively, which we use to improve a global fit of the effective Hamiltonian.

  • 26.
    Germann, Matthias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hjältén, Adrian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Boudon, Vincent
    Laboratoire ICB, UMR 6303, CNRS, Université Bourgogne Franche-Comté, Dijon, France.
    Richard, Cyril
    Laboratoire ICB, UMR 6303, CNRS, Université Bourgogne Franche-Comté, Dijon, France.
    Tennyson, Jonathan
    Department of Physics and Astronomy, University College London, London, United Kingdom.
    Yurchenko, Sergey
    Department of Physics and Astronomy, University College London, London, United Kingdom.
    Gordon, Iouli E.
    Center for Astrophysics, Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Pett, Christian
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Krzempek, Karol
    Faculty of Electronics Photonics and Microsystems, Wrocław University of Science and Technology, Wroclaw, Poland.
    Hudzikowski, Arkadiusz
    Faculty of Electronics Photonics and Microsystems, Wrocław University of Science and Technology, Wroclaw, Poland.
    Głuszek, Aleksander
    Faculty of Electronics Photonics and Microsystems, Wrocław University of Science and Technology, Wroclaw, Poland.
    Soboń, Grzegorz
    Faculty of Electronics Photonics and Microsystems, Wrocław University of Science and Technology, Wroclaw, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    High accuracy line lists of CH4 and H2CO in the 8 µm range from optical frequency comb fourier transform spectroscopy2023In: 2023 conference on lasers and electro-optics Europe & European quantum electronics conference (CLEO/Europe-EQEC), IEEE, 2023, article id 10232703Conference paper (Refereed)
  • 27.
    Germann, Matthias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hjältén, Adrian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Gordon, Iouli E.
    Center for Astrophysics, Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Tennyson, Jonathan
    Department of Physics and Astronomy, University College London, London, United Kingdom.
    Yurchenko, Sergey
    Department of Physics and Astronomy, University College London, London, United Kingdom.
    Krzempek, Karol
    Faculty of Electronics, Photonics and Microsystems, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Hudzikowski, Arkadiusz
    Faculty of Electronics, Photonics and Microsystems, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Gluszek, Aleksander
    Faculty of Electronics, Photonics and Microsystems, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Pett, Christian
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Soboii, Grzegorz
    Faculty of Electronics, Photonics and Microsystems, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Precision frequency comb spectroscopy in the 8 µm range2023In: CLEO 2023: proceedings, Optical Society of America, 2023, article id AW4E.1Conference paper (Refereed)
    Abstract [en]

    We use Fourier transform spectroscopy based on a compact difference frequency generation comb source emitting around 8 μm to record broadband high-resolution spectra of molecules relevant to astrophysics and environmental monitoring. From the spectra we obtain line lists with sub-MHz accuracy, an order of magnitude better than previously available, and use them to refine theoretical models of these molecules. Here we report results for formaldehyde, for which the 8 μm range is missing in HITRAN.

  • 28.
    Germann, Matthias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hjältén, Adrian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Krzempek, Karol
    Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Hudzikowski, Arkadiusz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Gluszek, Aleksander
    Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Tomaszewska, Dorota
    Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Sobon, Grzegorz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Frequency comb fourier transform spectroscopy at 8 µm using a compact difference frequency generation source2021In: 2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), IEEE, 2021Conference paper (Refereed)
  • 29.
    Germann, Matthias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hjältén, Adrian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Krzempek, Karol
    Laser Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Hudzikowski, Arkadiusz
    Laser Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Gluszek, Aleksander
    Laser Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Tomaszewska, Dorota
    Laser Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Sobon, Grzegorz
    Laser Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Frequency Comb Fourier Transform Spectroscopy at 8m Using a Compact Difference Frequency Generation Source2021In: 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021, IEEE Lasers and Electro-Optics Society, 2021Conference paper (Refereed)
    Abstract [en]

    Mid-infrared comb-based Fourier transform spectroscopy allows high-resolution measurements of entire molecular absorption bands. However, most previous implementations were limited to wavelengths <5m. We present a Fourier transform spectrometer (FTS) with a comb-mode-limited resolution based on a compact difference frequency generation (DFG) source operating around 8m. We measure the spectrum of the ν 1 band of N 2 O in the Doppler limit and retrieve line center frequencies with precision of the order of 100 kHz.

  • 30.
    Germann, Matthias
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hjältén, Adrian
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Tennyson, Jonathan
    Department of Physics and Astronomy, University College London, Gower Street, London, United Kingdom.
    Yurchenko, Sergei N.
    Department of Physics and Astronomy, University College London, Gower Street, London, United Kingdom.
    Gordon, Iouli E.
    Center for Astrophysics, Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Pett, Christian
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Krzempek, Karol
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Hudzikowski, Arkadiusz
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Głuszek, Aleksander
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Soboń, Grzegorz
    Laser & Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Optical frequency comb Fourier transform spectroscopy of formaldehyde in the 1250 to 1390 cm−1 range: experimental line list and improved MARVEL analysis2024In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 312, article id 108782Article in journal (Refereed)
    Abstract [en]

    We use optical frequency comb Fourier transform spectroscopy to record high-resolution, low-pressure, room-temperature spectra of formaldehyde (H212C16O) in the range of 1250 to 1390 cm−1. Through line-by-line fitting, we retrieve line positions and intensities of 747 rovibrational transitions: 558 from the ν6 band, 129 from the ν4 band, and 14 from the ν3 band, as well as 46 from four different hot bands. We incorporate the accurate and precise line positions (0.4 MHz median uncertainty) into the MARVEL (measured active vibration-rotation energy levels) analysis of the H2CO spectrum. This increases the number of MARVEL-predicted energy levels by 82 and of rovibrational transitions by 5382, and substantially reduces uncertainties of MARVEL-derived H2CO energy levels over a large range: from pure rotational levels below 200 cm−1 up to multiply excited vibrational levels at 6000 cm−1. This work is an important step toward filling the gaps in formaldehyde data in the HITRAN database.

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  • 31. Gluszek, Aleksander
    et al.
    Vieira, Francisco Senna
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hudzikowski, Arkadiusz
    Waz, Adam
    Sotor, Jaroslaw
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sobon, Grzegorz
    Compact mode-locked Er-doped fiber laser for broadband cavity-enhanced spectroscopy2020In: Applied physics. B, Lasers and optics (Print), ISSN 0946-2171, E-ISSN 1432-0649, Vol. 126, no 8, article id 137Article in journal (Refereed)
    Abstract [en]

    We report the design and characteristics of a simple and compact mode-locked Er-doped fiber laser and its application to broadband cavity-enhanced spectroscopy. The graphene mode-locked polarization maintaining oscillator consumes less than 5 W of power. It is thermally stabilized, enclosed in a 3D printed box, and equipped with three actuators that control the repetition rate: fast and slow fiber stretchers, and metal-coated fiber section. This allows wide tuning of the repetition rate and its stabilization to an external reference source. The applicability of the laser to molecular spectroscopy is demonstrated by detecting CO(2)in air using continuous-filtering Vernier spectroscopy with absorption sensitivity of 5.5 x 10(-8)cm(-1)in 50 ms.

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  • 32.
    Gordon, I.E.
    et al.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Rothman, L.S.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Hargreaves, R.J.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Hashemi, R.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Karlovets, E.V.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Skinner, F.M.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Conway, E.K.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Hill, C.
    Nuclear Data Section, International Atomic Energy Agency, Vienna International Centre, PO Box 100, Vienna, Austria.
    Kochanov, R.V.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States; V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation; QUAMER laboratory, Tomsk State University, Tomsk, Russian Federation.
    Tan, Y.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States; Hefei National Laboratory for Physical Science at Microscale, University of Science and Technology of China, Hefei, China.
    Wcisło, P.
    Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Torun, Grudziadzka 5, Torun, Poland.
    Finenko, A.A.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States; Department of Chemistry, Lomonosov Moscow State University, Moscow, Russian Federation.
    Nelson, K.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Bernath, P.F.
    Department of Chemistry, Old Dominion University, VA, Norfolk, United States.
    Birk, M.
    German Aerospace Center (DLR), Remote Sensing Technology Institute, Wessling, Germany.
    Boudon, V.
    Laboratoire Interdisciplinaire Carnot de Bourgogne, Université de Bourgogne Franche-Comté, UMR 6303 CNRS, Dijon Cedex, France.
    Campargue, A.
    University of Grenoble Alpes, CNRS, LIPhy, Grenoble, France.
    Chance, K.V.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Coustenis, A.
    Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Paris Observatory, CNRS, PSL University, Sorbonne University, Paris, France.
    Drouin, B.J.
    Jet Propulsion Laboratory, California Institute of Technology, CA, Pasadena, United States.
    Flaud, J.M.
    Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France.
    Gamache, R.R.
    Department of Environmental, Earth & Atmospheric Sciences, University of Massachusetts, MA, Lowell, United States.
    Hodges, J.T.
    Chemical Sciences Division, National Institute of Standards and Technology, MD, Gaithersburg, United States.
    Jacquemart, D.
    Sorbonne Université, CNRS, De la MOlécule aux NAno-objets : Réactivité, Interactions et Spectroscopies, MONARIS, Paris, France.
    Mlawer, E.J.
    Atmospheric and Environmental Research, MA, Lexington, United States.
    Nikitin, A.V.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Perevalov, V.I.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Rotger, M.
    Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 7331, BP 1039, Reims Cedex 2, France.
    Tennyson, J.
    Department of Physics and Astronomy, University College London, London, United Kingdom.
    Toon, G.C.
    Jet Propulsion Laboratory, California Institute of Technology, CA, Pasadena, United States.
    Tran, H.
    Laboratoire de Météorologie Dynamique/IPSL, CNRS, Sorbonne Université, École normale supérieure, PSL Research University, École polytechnique, Paris, France.
    Tyuterev, V.G.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation; QUAMER laboratory, Tomsk State University, Tomsk, Russian Federation; Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 7331, BP 1039, Reims Cedex 2, France.
    Adkins, E.M.
    Chemical Sciences Division, National Institute of Standards and Technology, MD, Gaithersburg, United States.
    Baker, A.
    Division of Astronomy, California Institute of Technology, CA, Pasadena, United States.
    Barbe, A.
    Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 7331, BP 1039, Reims Cedex 2, France.
    Canè, E.
    Dipartimento di Chimica Industriale “Toso Montanari”, Università di Bologna, Viale Risorgimento 4, Bologna, Italy.
    Császár, A.G.
    MTA-ELTE Complex Chemical Systems Research Group, Budapest, Hungary; Eötvös Loránd University, Institute of Chemistry, Budapest, Hungary.
    Dudaryonok, A.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Egorov, O.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Fleisher, A.J.
    Chemical Sciences Division, National Institute of Standards and Technology, MD, Gaithersburg, United States.
    Fleurbaey, H.
    University of Grenoble Alpes, CNRS, LIPhy, Grenoble, France.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Furtenbacher, T.
    MTA-ELTE Complex Chemical Systems Research Group, Budapest, Hungary.
    Harrison, J.J.
    Department of Physics and Astronomy, University of Leicester, Leicester, United Kingdom; University of Leicester, National Centre for Earth Observation, Leicester, United Kingdom; University of Leicester, Leicester Institute for Space and Earth Observation, Leicester, United Kingdom.
    Hartmann, J.M.
    Laboratoire de Météorologie Dynamique/IPSL, CNRS, École polytechnique, Sorbonne Université, École normale supérieure, PSL Research University, Palaiseau, France.
    Horneman, V.M.
    Department of Physics, University of Oulu, Finland.
    Huang, X.
    SETI Institute, CA, Mountain View, United States.
    Karman, T.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States.
    Karns, J.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States; Golisano College of Computing and Information Sciences, Rochester Institute of Technology, NY, Rochester, United States; Computer Science Department, State University of New York at Oswego, NY, Oswego, United States.
    Kassi, S.
    University of Grenoble Alpes, CNRS, LIPhy, Grenoble, France.
    Kleiner, I.
    Université de Paris and Univ Paris Est Creteil, CNRS, LISA, Paris, France.
    Kofman, V.
    NASA Goddard Space Flight Center, MD, Greenbelt, United States.
    Kwabia-Tchana, F.
    Université de Paris and Univ Paris Est Creteil, CNRS, LISA, Paris, France.
    Lavrentieva, N.N.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Lee, T.J.
    Planetary Systems Branch, Space Science and Astrobiology Division, NASA Ames Research Center, CA, Moffett Field, United States.
    Long, D.A.
    Chemical Sciences Division, National Institute of Standards and Technology, MD, Gaithersburg, United States.
    Lukashevskaya, A.A.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Lyulin, O.M.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Makhnev, V.Yu.
    Institute of Applied Physics of Russian Academy of Sciences, Nizhny Novgorod, Russian Federation.
    Matt, W.
    Center for Astrophysics |Harvard & Smithsonian, Atomic and Molecular Physics Division, MA, Cambridge, United States; Computer Science Department, State University of New York at Oswego, NY, Oswego, United States.
    Massie, S.T.
    University of Colorado, Laboratory for Atmospheric and Space Physics, CO, Boulder, United States.
    Melosso, M.
    Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via F. Selmi 2, Bologna, Italy.
    Mikhailenko, S.N.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Mondelain, D.
    University of Grenoble Alpes, CNRS, LIPhy, Grenoble, France.
    Müller, H.S.P.
    I. Physikalisches Institut, Universität zu Köln, Köln, Germany.
    Naumenko, O.V.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Perrin, A.
    Laboratoire de Météorologie Dynamique/IPSL, CNRS, Sorbonne Université, École normale supérieure, PSL Research University, École polytechnique, Paris, France.
    Polyansky, O.L.
    Department of Physics and Astronomy, University College London, London, United Kingdom; Institute of Applied Physics of Russian Academy of Sciences, Nizhny Novgorod, Russian Federation.
    Raddaoui, E.
    Sorbonne Université, CNRS, De la MOlécule aux NAno-objets : Réactivité, Interactions et Spectroscopies, MONARIS, Paris, France.
    Raston, P.L.
    Department of Chemistry and Biochemistry, James Madison University, VA, Harrisonburg, United States; Department of Chemistry, University of Adelaide, South Australia, Australia.
    Reed, Z.D.
    Chemical Sciences Division, National Institute of Standards and Technology, MD, Gaithersburg, United States.
    Rey, M.
    Groupe de Spectrométrie Moléculaire et Atmosphérique, UMR CNRS 7331, BP 1039, Reims Cedex 2, France.
    Richard, C.
    Laboratoire Interdisciplinaire Carnot de Bourgogne, Université de Bourgogne Franche-Comté, UMR 6303 CNRS, Dijon Cedex, France.
    Tóbiás, R.
    MTA-ELTE Complex Chemical Systems Research Group, Budapest, Hungary.
    Sadiek, I.
    Umeå University, Faculty of Science and Technology, Department of Physics. Leibniz Institute for Plasma Science and Technology (INP), Greifswald, Germany.
    Schwenke, D.W.
    Planetary Systems Branch, Space Science and Astrobiology Division, NASA Ames Research Center, CA, Moffett Field, United States.
    Starikova, E.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Sung, K.
    Jet Propulsion Laboratory, California Institute of Technology, CA, Pasadena, United States.
    Tamassia, F.
    Dipartimento di Chimica Industriale “Toso Montanari”, Università di Bologna, Viale Risorgimento 4, Bologna, Italy.
    Tashkun, S.A.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Vander Auwera, J.
    Université Libre de Bruxelles, Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), C.P. 160/09, Brussels, Belgium.
    Vasilenko, I.A.
    V.E. Zuev Institute of Atmospheric Optics, Laboratory of Theoretical Spectroscopy, Russian Academy of Sciences, Tomsk, Russian Federation.
    Vigasin, A.A.
    Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Pyzhevsky per. 3, Moscow, Russian Federation.
    Villanueva, G.L.
    NASA Goddard Space Flight Center, MD, Greenbelt, United States.
    Vispoel, B.
    Department of Environmental, Earth & Atmospheric Sciences, University of Massachusetts, MA, Lowell, United States; Research Unit Lasers and Spectroscopies (LLS), Institute of Life, Earth and Environment (ILEE), University of Namur (UNamur), Namur, Belgium; Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium.
    Wagner, G.
    German Aerospace Center (DLR), Remote Sensing Technology Institute, Wessling, Germany.
    Yachmenev, A.
    Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg, Germany; Hamburg Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, Hamburg, Germany.
    Yurchenko, S.N.
    Department of Physics and Astronomy, University College London, London, United Kingdom.
    The HITRAN2020 molecular spectroscopic database2022In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 277, article id 107949Article in journal (Refereed)
    Abstract [en]

    The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years). All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules. The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition.

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  • 33.
    Hjältén, Adrian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sadiek, Ibrahim
    Umeå University, Faculty of Science and Technology, Department of Physics. Leibniz Institute for Plasma Science and Technology (INP), Greifswald, Germany.
    Line positions and intensities of the ν1 band of 12CH3I using mid-infrared optical frequency comb Fourier transform spectroscopy2023In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 306, article id 108646Article in journal (Refereed)
    Abstract [en]

    We present a new spectral analysis of the ν1 and ν3+ν1−ν3 bands of 12CH3I around 2971 cm−1 based on a high-resolution spectrum spanning from 2800 cm–1 to 3160 cm–1, measured using an optical frequency comb Fourier transform spectrometer. From this spectrum, we previously assigned the ν4 and ν3+ν4−ν3 bands around 3060 cm–1 using PGOPHER, and the line list was incorporated in the HITRAN database. Here, we treat the two fundamental bands, ν1 and ν4, together with the perturbing states, 2ν2+ν3 and ν2+2ν6±2, as a four-level system connected via Coriolis and Fermi interactions. A similar four-level system is assumed to connect the two ν3+ν1−ν3 and ν3+ν4−ν3 hot bands, which appear due to the population of the low-lying ν3 state at room temperature, with the 2ν2+2ν3 and ν2+ν3+2ν6±2 perturbing states. This spectroscopic treatment provides a good global agreement of the simulated spectra with experiment, and hence accurate line lists and band parameters of the four connected vibrational states in each system. It also allows revisiting the analysis of the ν4 and ν3+ν4−ν3 bands, which were previously treated as separate bands, not connected to their ν1 and ν3+ν1−ν3 counterparts. Overall, we assign 4665 transitions in the fundamental band system, with an average error of 0.00071 cm–1, a factor of two better than earlier work on the ν1 band using conventional Fourier transform infrared spectroscopy. The ν1 band shows hyperfine splitting, resolvable for transitions with J ≤ 2 × K. Finally, the spectral intensities of 65 lines of the ν1 band and 7 lines of the ν3+ν1−ν3 band are reported for the first time using the Voigt line shape as a model in multispectral fitting. The reported line lists and intensities will serve as a reference for high-resolution molecular spectroscopic databases, and as a basis for line selection in future monitoring applications of CH3I.

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  • 34.
    Hjältén, Adrian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Germann, Matthias
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Krzempek, Karol
    Laser & Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Hudzikowski, Arkadiusz
    Laser & Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Głuszek, Aleksander
    Laser & Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Tomaszewska, Dorota
    Laser & Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Soboń, Grzegorz
    Laser & Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Optical frequency comb Fourier transform spectroscopy of 14N216O at 7.8 µm2021In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 271, article id 107734Article in journal (Refereed)
    Abstract [en]

    We use a Fourier transform spectrometer based on a compact mid-infrared difference frequency generation comb source to perform broadband high-resolution measurements of nitrous oxide, 14N216O, and retrieve line center frequencies of the ν1 fundamental band and the ν1 + ν2 – ν2 hot band. The spectrum spans 90 cm−1 around 1285 cm−1 with a sample point spacing of 3 × 10−4 cm−1 (9 MHz). We report line positions of 72 lines in the ν1 fundamental band between P(37) and R(38), and 112 lines in the ν1 + ν2 – ν2 hot band (split into two components with e/f rotationless parity) between P(34) and R(33), with uncertainties in the range of 90-600 kHz. We derive upper state constants of both bands from a fit of the effective ro-vibrational Hamiltonian to the line center positions. For the fundamental band, we observe excellent agreement in the retrieved line positions and upper state constants with those reported in a recent study by AlSaif et al. using a comb-referenced quantum cascade laser [J Quant Spectrosc Radiat Transf, 2018;211:172-178]. We determine the origin of the hot band with precision one order of magnitude better than previous work based on FTIR measurements by Toth [http://mark4sun.jpl.nasa.gov/n2o.html], which is the source of the HITRAN2016 data for these bands.

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  • 35.
    Hjältén, Adrian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Germann, Matthias
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Krzempek, Karol
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Hudzikowski, Arkadiusz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Głuszek, Aleksander
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Tomaszewska, Dorota
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Soboń, Grzegorz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Precision measurements of 14N216O using a comb-based fourier transform spectrometer at 7.8 µm2021In: CLEO: Science and Innovations: Conference Proceedings, Optical Society of America, 2021, article id SM1C.4Conference paper (Refereed)
    Abstract [en]

    Using a compact fiber-based difference frequency generation comb and a Fourier transform spectrometer we record spectra of the N2O ν1 band at 1285 cm-1 in the Doppler limit. Fitting Gaussian line shapes to the individual absorption lines yields center frequencies with <200 kHz average precision.

  • 36.
    Hjältén, Adrian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Germann, Matthias
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sadiek, Ibrahim
    Leibniz Institute for Plasma Science and Technology (INP), Greifswald, Germany.
    Lu, Chuang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Vieira, Francisco Senna
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Krzempek, Karol
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Hudzikowski, Arkadiusz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Głuszek, Aleksander
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Tomaszewska, Dorota
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Stuhr, Michael
    Institute of Physical Chemistry, University of Kiel, Kiel, Germany.
    Soboń, Grzegorz
    Laser and Fiber Electronics Group, Faculty of Electronics, Wrocław University of Science and Technology, Wroclaw, Poland.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Fourier transform spectroscopy using difference frequency generation comb sources at 3.3 µm and 7.8 µm2021In: Proceedings OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES), Optical Society of America, 2021, article id JTu4D.3Conference paper (Refereed)
    Abstract [en]

    We use offset-frequency-free difference frequency generation comb sources and a Fourier transform spectrometer with comb-mode-width limited resolution to measure and analyze spectra of molecular species of atmospheric relevance: CH3I and CH2Br2 around 3000 cm-1, and 14N216O around 1280 cm-1

  • 37.
    Hjältén, Adrian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sadiek, Ibrahim
    Leibniz Institute for Plasma Science and Technology (INP), Greifswald, Germany.
    Lu, Chuang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Vieira, Francisco Senna
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Stuhr, Michael
    Institute of Physical Chemistry, University of Kiel, Kiel, Germany.
    Germann, Matthias
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    High-Resolution Measurements of Halogenated Volatile Organic Compounds Using Frequency Comb Fourier Transform Spectroscopy2021In: 2021 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference, CLEO/Europe-EQEC 2021, IEEE Lasers and Electro-Optics Society, 2021Conference paper (Refereed)
    Abstract [en]

    Halogenated volatile organic compounds (HVOCs) play an important role in the photo-chemistry of the atmosphere, for example in ozone depletion [1]. They are produced naturally in the oceans but are also used in industrial and agricultural applications where they may pose a health-hazard due to their biological effects. Optical detection of these compounds would hence be of great value in, for example, atmospheric monitoring and leak detection in workplaces. Crucial for such detection schemes is access to accurate spectroscopic models, which in turn require high-precision laboratory measurements. Due to the combination of broad spectral coverage and high resolution, optical frequency comb Fourier transform spectroscopy is an excellent tool for providing the necessary spectroscopic data. We use a mid-infrared frequency comb and a Fourier transform spectrometer (FTS) to measure and assign high-resolution spectra of multiple absorption bands of two HVOCs: methyl iodide, CH 3 I [2] , and dibromomethane, CH 2 Br 2 , around 3.3m.

  • 38.
    Hjältén, Adrian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silva de Oliveira, Vinicius
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rosina, Andrea
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Université de Rennes, CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, Rennes, France..
    Soboń, Grzegorz
    Laser and Fiber Electronics Group, Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wroclaw, Poland..
    Lehmann, Kevin
    Departments of Chemistry and Physics, University of Virginia, VA, Charlottesville, United States..
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Accurate measurement and assignment of high rotational energy levels in the 9150 - 9370 cm−1 range of methane using optical frequency comb double-resonance spectroscopyManuscript (preprint) (Other academic)
  • 39.
    Hjältén, Adrian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silva de Oliveira, Vinicius
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rosina, Andrea
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Univ Rennes, CNRS, IPR (Institut de Physique de Rennes), UMR 6251, Rennes, France.
    Sobon, Grzegorz
    Faculty of Electronics, Photonics and Microsystems, Wroclaw University of Science and Technology, Wroclaw, Poland.
    Lehmann, Kevin K.
    Department of Chemistry & Physics, University of Virginia, VA, Charlottesville, United States.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Accurate measurement and assignment of high rotational energy levels of the 3v3 ← v3 band of methane2023In: 2023 conference on lasers and electro-optics, CLEO 2023, IEEE, 2023, article id STh4L.4Conference paper (Refereed)
    Abstract [en]

    We use optical-optical double-resonance spectroscopy with a high-power continuous wave pump and a cavity-enhanced comb probe to expand sub-Doppler measurements of the 3v3 ← v3 band of CH4 to higher rotational levels. We assign the final states using combination differences, i.e., by reaching the same state using different pump/probe combinations.

  • 40.
    Hjältén, Adrian
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silva de Oliveira, Vinicius
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Silander, Isak
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rosina, Andrea
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Univ Rennes, CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, Rennes, France.
    Soboń, Grzegorz
    Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, Wrocław, Poland.
    Lehmann, Kevin K.
    Departments of Chemistry & Physics, University of Virginia, VA, Charlottesville, United States.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Accurate measurement and assignment of high rotational energy levels of the 3ν3 ← ν3 band of methane2023In: CLEO 2023, Optical Society of America, 2023Conference paper (Refereed)
    Abstract [en]

    We use optical-optical double-resonance spectroscopy with a high-power continuous wave pump and a cavity-enhanced comb probe to expand sub-Doppler measurements of the 3ν3←ν3 band of CH4 to higher rotational levels. We assign the final states using combination differences, i.e., by reaching the same state using different pump/probe combinations.

  • 41.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Filipsson, Anna
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Maslowski, Piotr
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    CO2 Line Parameter Retrieval Beyond the Voigt Profile Using Comb-Based Fourier Transform Spectroscopy2018In: Conference on Lasers and Electro-Optics, Optical Society of America, 2018Conference paper (Refereed)
    Abstract [en]

    We measure absorption spectra of the CO213 band at 1.57 μm using optical frequency comb Fourier transform spectroscopy with sub-nominal resolution and retrieve line shape parameters using multiline fitting with the speed-dependent Voigt profile.

  • 42.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Khodabakhsh, Amir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Fourier-transform-based noise-immune cavity-enhanced optical frequency comb spectroscopy2016In: Light, Energy and the Environment, Optica Publishing Group (formerly OSA) , 2016, article id JW4A.13Conference paper (Refereed)
    Abstract [en]

    We describe the principles and implementation of Fourier-transform-based cavityenhanced optical frequency comb spectroscopy that uses phase modulation at the cavity free spectral range frequency to achieve high sensitivity over broad spectral range.

  • 43.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Filipsson, Anna
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hausmaninger, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Zhao, Gang
    Umeå University, Faculty of Science and Technology, Department of Physics. 2 State Key Laboratory of Quantum Optics and Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Broadband calibration-free cavity-enhanced complex refractive index spectroscopy using a frequency comb2018In: Optics Express, E-ISSN 1094-4087, Vol. 26, no 16, p. 20633-20648Article in journal (Refereed)
    Abstract [en]

    We present broadband cavity-enhanced complex refractive index spectroscopy (CE-CRIS), a technique for calibration-free determination of the complex refractive index of entire molecular bands via direct measurement of transmission modes of a Fabry-Perot cavity filled with the sample. The measurement of the cavity transmission spectrum is done using an optical frequency comb and a mechanical Fourier transform spectrometer with sub-nominal resolution. Molecular absorption and dispersion spectra (corresponding to the imaginary and real parts of the refractive index) are obtained from the cavity mode broadening and shift retrieved from fits of Lorentzian profiles to the individual cavity modes. This method is calibration-free because the mode broadening and shift are independent of the cavity parameters such as the length and mirror reflectivity. In this first demonstration of broadband CE-CRIS we measure simultaneously the absorption and dispersion spectra of three combination bands of CO2 in the range between 1525 nm and 1620 nm and achieve good agreement with theoretical models. This opens up for precision spectroscopy of the complex refractive index of several molecular bands simultaneously. 

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  • 44.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Filipsson, Anna
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hausmaninger, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Zhao, Gang
    Umeå University, Faculty of Science and Technology, Department of Physics. Institute of Laser Spectroscopy, Shanxi University, Taiyuan, China.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Broadband Complex Refractive Index Spectroscopy via Measurement of Cavity Modes2018In: 2018 Conference on Lasers and Electro-Optics (CLEO), IEEE, 2018Conference paper (Refereed)
    Abstract [en]

    We retrieve high precision absorption and dispersion spectra of the 3v(1)+v(3) band of CO2 from direct measurement of cavity transmission modes using an optical frequency comb and a mechanical Fourier transfolin spectrometer with sub-nominal resolution.

  • 45.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Filipsson, Anna
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hausmaninger, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Zhao, Gang
    Umeå University, Faculty of Science and Technology, Department of Physics. Institute of Laser Spectroscopy, Shanxi University, Taiyuan, China.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Cavity-enhanced complex refractive index spectroscopy of entire molecular bands using a frequency comb2018In: Optics InfoBase Conference Papers, Optica Publishing Group , 2018, article id JT2A.29Conference paper (Refereed)
    Abstract [en]

    We demonstrate broadband calibration-free complex refractive index spectroscopy of entire molecular bands by direct measurement of transmission modes of a Fabry-Perot cavity using frequency comb-based Fourier transform spectrometer with sub-nominal resolution.

  • 46.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Khodabakhsh, Amir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Signal line shapes of Fourier-transform cavity-enhanced frequency modulation spectroscopy with optical frequency combs2017In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 34, no 2, p. 358-365Article in journal (Refereed)
    Abstract [en]

    We present a thorough analysis of the signal line shapes of Fourier-transform-based noise-immune cavity-enhanced optical frequency comb spectroscopy (NICE-OFCS). We discuss the signal dependence on the ratio of the modulation frequency, f(m), to the molecular linewidth, G. We compare a full model of the signals and a simplified absorption-like analytical model that has high accuracy for low f(m)/G ratios and is much faster to compute. We verify the theory experimentally by measuring and fitting the NICE-OFCS spectra of CO2 at 1575 nm using a system based on an Er: fiber femtosecond laser and a cavity with a finesse of similar to 11000. 

  • 47.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics. University of Rennes, CNRS, IPR Inst Phys Rennes, Rennes, France.
    Maslowski, Piotr
    Filipsson, Anna
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hausmaninger, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Zhao, Gang
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Precise comb-based fourier transform spectroscopy for line parameter retrieval2019In: 2019 Conference on Lasers and Electro-Optics Europe and European Quantum Electronics Conference (CLEO/EUROPE-EQEC), Institute of Electrical and Electronics Engineers (IEEE), 2019, article id 8872655Conference paper (Refereed)
    Abstract [en]

    Accurate parameters of molecular transitions are needed for data analysis in many applications, ranging from atmospheric research to astrophysics and determination of fundamental constants. Optical frequency comb Fourier transform spectroscopy (OFC-FTS) is particularly well-suited for high-precision measurements of broadband molecular spectra. From these spectra, the parameters of individual transitions - all measured simultaneously under the same experimental conditions - can be determined. We use a mechanical OFC-FTS spectrometer with sub-nominal resolution [1, 2] to perform precise broadband measurements of entire molecular bands of CO2 using either direct absorption spectroscopy or cavity-enhanced complex refractive index spectroscopy (CE-CRIS) [3] and we extract line parameters for line shapes beyond the Voigt profile.

  • 48.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Westberg, Jonas
    Khodabakhsh, Amir
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Rutkowski, Lucile
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Wysocki, Gerard
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Faraday rotation spectroscopy using an optical frequency comb2017In: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), IEEE, 2017Conference paper (Refereed)
    Abstract [en]

    Summary form only given. The mid-infrared (MIR) part of the optical spectrum (3-12 μm) houses the fundamental absorption bands of a multitude of environmentally important molecules, but the abundance of water absorption often causes interference with the target species and makes concentration measurement inaccurate. The broad spectral coverage of optical frequency comb spectroscopy (OFCS) provides access to entire ro-vibrational bands and allows more accurate concentration quantification and retrieval of sample temperature. To further improve detection sensitivity of paramagnetic species in the presence of interfering species, we combine a MIR optical frequency comb with the Faraday rotation spectroscopy (FRS) technique [I], which is insensitive to interferences from diamagnetic molecules, such as H 2 O, CO 2 , and CO. In FRS, the rotation of the polarization induced by an external magnetic field in the vicinity of paramagnetic molecular transitions is translated to an intensity change by the use of a polarization analyzer, which effectively removes the influence of any non-paramagnetic species. In the proof of principle demonstration of OFC-FRS we detect nitric oxide (NO) in the presence of water at 5.3 μm using a Fourier transform spectrometer.

  • 49.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Westberg, Jonas
    Department of Electrical Engineering, Princeton University, NJ, Princeton, United States.
    Wysocki, Gerard
    Department of Electrical Engineering, Princeton University, NJ, Princeton, United States.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Optical frequency comb faraday rotation spectroscopy2018In: Proceedings Conference on Lasers and Electro-Optics, Optica Publishing Group (formerly OSA) , 2018, article id JW2A.165Conference paper (Refereed)
    Abstract [en]

    By combining Faraday rotation spectroscopy with an optical frequency comb Fourier transform spectrometer, we measure background- and calibration-free spectra of the entire Q- and R-branches of the fundamental band of nitric oxide at 1850-1920 cm-1.

  • 50.
    Johansson, Alexandra C.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Westberg, Jonas
    Department of Electrical Engineering, Princeton University, NJ, Princeton, United States.
    Wysocki, Gerard
    Department of Electrical Engineering, Princeton University, NJ, Princeton, United States.
    Foltynowicz, Aleksandra
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Optical frequency comb faraday rotation spectroscopy2018In: 2018 Conference on Lasers and Electro-Optics, CLEO 2018 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2018, article id 8427419Conference paper (Refereed)
    Abstract [en]

    By combining Faraday rotation spectroscopy with an optical frequency comb Fourier transform spectrometer, we measure background- and calibration-free spectra of the entire Q- and R-branches of the fundamental band of nitric oxide at 1850-1920 cm-1.

123 1 - 50 of 124
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