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Khodabakhsh, Amir
Publications (10 of 25) Show all publications
Rutkowski, L., Masłowski, P., Johansson, A. C., Khodabakhsh, A. & Foltynowicz, A. (2018). Optical frequency comb Fourier transform spectroscopy with sub-nominal resolution and precision beyond the Voigt profile. Journal of Quantitative Spectroscopy and Radiative Transfer, 204, 63-73
Open this publication in new window or tab >>Optical frequency comb Fourier transform spectroscopy with sub-nominal resolution and precision beyond the Voigt profile
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2018 (English)In: Journal of Quantitative Spectroscopy and Radiative Transfer, ISSN 0022-4073, E-ISSN 1879-1352, Vol. 204, p. 63-73Article in journal (Refereed) Published
Abstract [en]

Broadband precision spectroscopy is indispensable for providing high fidelity molecular parameters for spectroscopic databases. We have recently shown that mechanical Fourier transform spectrometers based on optical frequency combs can measure broadband high-resolution molecular spectra undistorted by the instrumental line shape (ILS) and with a highly precise frequency scale provided by the comb. The accurate measurement of the power of the comb modes interacting with the molecular sample was achieved by acquiring single-burst interferograms with nominal resolution matched to the comb mode spacing. Here we describe in detail the experimental and numerical steps needed to achieve sub-nominal resolution and retrieve ILS-free molecular spectra, i.e. with ILS-induced distortion below the noise level. We investigate the accuracy of the transition line centers retrieved by fitting to the absorption lines measured using this method. We verify the performance by measuring an ILS-free cavity-enhanced low-pressure spectrum of the 3ν1 + ν3 band of CO2 around 1575 nm with line widths narrower than the nominal resolution. We observe and quantify collisional narrowing of absorption line shape, for the first time with a comb-based spectroscopic technique. Thus retrieval of line shape parameters with accuracy not limited by the Voigt profile is now possible for entire absorption bands acquired simultaneously.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Optical frequency combs, Fourier transform spectroscopy, High resolution spectroscopy, Line shapes
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-142443 (URN)10.1016/j.jqsrt.2017.09.001 (DOI)000414880500009 ()
Available from: 2017-12-06 Created: 2017-12-06 Last updated: 2018-11-13Bibliographically approved
Rutkowski, L., Johansson, A. C., Khodabakhsh, A. & Foltynowicz, A. (2017). Broadband and High Resolution Direct Measurement of Cavity Resonances. In: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC): . Paper presented at Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), JUN 25-29, 2017, Munich, GERMANY. IEEE
Open this publication in new window or tab >>Broadband and High Resolution Direct Measurement of Cavity Resonances
2017 (English)In: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), IEEE, 2017Conference paper, Published paper (Refereed)
Abstract [en]

Summary form only given. Optical frequency combs offer unprecedented combination of broad bandwidth and high resolution and their coupling to enhancement cavities provides high sensitivity for spectroscopic measurements. Here we use a frequency-comb-based Fourier transform spectrometer (FTS) to measure the narrow resonances of a high-finesse cavity over a bandwidth of 100 nm around 1.55 μm and derive the group delay dispersion (GDD) of the cavity mirrors with precision below 1 fs 2 from the cavity resonance frequencies. We do this using a method that allows precise sampling of the comb intensities using an FTS with nominal resolution matched to the comb repetition rate (f rep ) [1, 2], and we demonstrate that sub-MHz resolution is achieved.

Place, publisher, year, edition, pages
IEEE, 2017
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-152157 (URN)10.1109/CLEOE-EQEC.2017.8087461 (DOI)000432564601222 ()978-1-5090-6736-7 (ISBN)
Conference
Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), JUN 25-29, 2017, Munich, GERMANY
Funder
Swedish Research Council, 2016-03593Swedish Foundation for Strategic Research , ICA12-0031Knut and Alice Wallenberg Foundation, KAW 2015.0159
Available from: 2018-10-01 Created: 2018-10-01 Last updated: 2018-10-01Bibliographically approved
Khodabakhsh, A., Rutkowski, L., Morville, J., Johansson, A. C., Soboń, G. & Foltynowicz, A. (2017). Cavity-Enhanced Continuous-Filtering Vernier Spectroscopy at 3.3 mu m using a Femtosecond Optical Parametric Oscillator. In: 2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS EUROPE & EUROPEAN QUANTUM ELECTRONICS CONFERENCE (CLEO/EUROPE-EQEC): . Paper presented at 2017 European Conference on Lasers and Electro-Optics and European Quantum Electronics Conference, Munich Germany, 25–29 June 2017 (pp. CH_2_2). IEEE
Open this publication in new window or tab >>Cavity-Enhanced Continuous-Filtering Vernier Spectroscopy at 3.3 mu m using a Femtosecond Optical Parametric Oscillator
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2017 (English)In: 2017 CONFERENCE ON LASERS AND ELECTRO-OPTICS EUROPE & EUROPEAN QUANTUM ELECTRONICS CONFERENCE (CLEO/EUROPE-EQEC), IEEE , 2017, p. CH_2_2-Conference paper, Published paper (Refereed)
Abstract [en]

Optical frequency comb spectroscopy in the mid-infrared fingerprint region combines broad spectral bandwidth with high detection sensitivity and allows simultaneous detection of trace amounts of many molecular species. We have recently demonstrated a continuous-filtering Vernier spectrometer based on a mid-infrared optical frequency comb and an enhancement cavity for fast and sensitive detection of CH4 [1]. Here we present an improved, fully automatized and frequency calibrated continuous-filtering Vernier spectrometer, schematically shown in Fig. 1(a). The comb source is a doubly resonant optical parametric oscillator (DROPO) based on an orientation-patterned GaAs crystal synchronously pumped by a Tm:fiber femtosecond laser (125 MHz repetition rate, frep). The signal comb (3.1–3.4 µm, 30 mW) is mode matched to a 60-cm long Vernier enhancement cavity with a finesse of ~350 at 3.25 μm, placed in an enclosure that can be filled with the gas sample. The output mirror is attached to a PZT and mounted on a translation stage. When the cavity free spectral range is perfectly matched to twice the frep (250 MHz) every other signal comb mode is transmitted through the cavity. By detuning the cavity length from this perfect match position the cavity resonances act as a filter and transmit groups of comb modes called Vernier orders [2]. A diffraction grating mounted on a galvo-scanner separates these orders after the cavity and the chosen order is sent to the detection system. The Vernier order is tuned across the signal comb spectrum by scanning the cavity length (at 20 Hz) and the grating is rotated synchronously to fix the order in space and allow acquisition of the entire spectrum in 25 ms. Any residual mismatch between the cavity length scan and the grating rotation is compensated by a feedback loop acting on the frep of the pump laser and the PZT of the Vernier cavity [2]. A Fabry-Perot etalon is used for frequency calibration of the spectrometer. Figure 1(b) shows in black the normalized transmission spectrum of a sample containing 5.0 ppm CH4 and 160 ppm water. The red and blue curves show the corresponding fit of the Vernier spectrum [3] of CH4 and water, respectively, calculated using Voigt profiles, line parameters from the HITRAN database, and the experimentally determined cavity finesse. The figure of merit of the spectrometer is 1×10−9cm−1 Hz−1∕2 per spectral element and multiline fitting yields minimum detectable concentration of CH4 of 2 ppb in 25 ms, translating into 400 ppt Hz−1∕2 Since the spectrum of the signal comb covers the fundamental C-H stretch transitions we expect low detection limits for other hydrocarbons as well. In conclusion, mid-infrared comb-based continuous-filtering Vernier spectroscopy allows fast and highly sensitive measurement of broadband absorption spectra using a robust and compact detection system.

Place, publisher, year, edition, pages
IEEE, 2017
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-155053 (URN)000432564600616 ()978-1-5090-6736-7 (ISBN)
Conference
2017 European Conference on Lasers and Electro-Optics and European Quantum Electronics Conference, Munich Germany, 25–29 June 2017
Available from: 2019-01-07 Created: 2019-01-07 Last updated: 2019-01-07Bibliographically approved
Khodabakhsh, A., Rutkowski, L., Morville, J., Johansson, A. C., Soboń, G. & Foltynowicz, A. (2017). Continuous-Filtering Vernier Spectroscopy at 3.3 mu m Using a Femtosecond Optical Parametric Oscillator. In: 2017 conference on lasers and elecro-optics (CLEO): Science and innovations. Paper presented at Conference on Lasers and Electro-Optics (CLEO), MAY 14-19, 2017, San Jose, CA. IEEE, Article ID SW1L.5.
Open this publication in new window or tab >>Continuous-Filtering Vernier Spectroscopy at 3.3 mu m Using a Femtosecond Optical Parametric Oscillator
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2017 (English)In: 2017 conference on lasers and elecro-optics (CLEO): Science and innovations, IEEE , 2017, article id SW1L.5Conference paper, Published paper (Refereed)
Abstract [en]

Using a cavity-enhanced continuous-filtering Vernier spectrometer based on a femtosecond optical parametric oscillator we measure broadband spectra of atmospheric water and CH4 around 3.3 mu m reaching 4 ppb detection limit for CH4 in 15 ms.

Place, publisher, year, edition, pages
IEEE, 2017
Series
Conference on Lasers and Electro-Optics, ISSN 2160-9020
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-146824 (URN)10.1364/CLEO_SI.2017.SW1L.5 (DOI)000427296203060 ()978-1-9435-8027-9 (ISBN)
Conference
Conference on Lasers and Electro-Optics (CLEO), MAY 14-19, 2017, San Jose, CA
Available from: 2018-04-23 Created: 2018-04-23 Last updated: 2018-06-09Bibliographically approved
Rutkowski, L., Johansson, A. C., Khodabakhsh, A., Valiev, D., Lodi, L., Yurchenko, S., . . . Foltynowicz, A. (2017). Detection of OH and H2O in an Atmospheric Flame by Near-Infrared Optical Frequency Comb Spectroscopy. In: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC): . Paper presented at Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), JUN 25-29, 2017, Munich, GERMANY. IEEE
Open this publication in new window or tab >>Detection of OH and H2O in an Atmospheric Flame by Near-Infrared Optical Frequency Comb Spectroscopy
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2017 (English)In: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), IEEE, 2017Conference paper, Published paper (Refereed)
Abstract [en]

Absorption spectroscopy is attractive for combustion diagnostics because it allows in-situ and calibration-free quantification of reactants/products and thermometry. However, spectra measured at atmospheric pressure in the near-infrared telecom range, where laser sources and optical components are readily available, suffer from strong water interference. Cavity-enhanced optical frequency comb spectroscopy (CE-OFCS) is well suited for detection of other species, as it provides broad bandwidth with high signal-to-noise ratio and resolution, and allows de-convolving the spectra hidden among water transitions. Here we report detection of OH in the presence of H2O in an atmospheric premixed methane/air flat flame by CE-OFCS at 1.57 μm. We demonstrate a new water line list that is more accurate than HITEMP [1] and we isolate the OH lines by dividing spectra taken at different heights above the burner (HABs) to retrieve OH concentration and flame temperature.

Place, publisher, year, edition, pages
IEEE, 2017
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-152156 (URN)10.1109/CLEOE-EQEC.2017.8086912 (DOI)000432564600671 ()978-1-5090-6736-7 (ISBN)
Conference
Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), JUN 25-29, 2017, Munich, GERMANY
Funder
Swedish Research Council, 621-2012-3650Swedish Foundation for Strategic Research , ICA12-0031Knut and Alice Wallenberg Foundation, KAW 2015.0159
Available from: 2018-10-01 Created: 2018-10-01 Last updated: 2018-10-01Bibliographically approved
Johansson, A. C., Westberg, J., Khodabakhsh, A., Rutkowski, L., Wysocki, G. & Foltynowicz, A. (2017). Faraday Rotation Spectroscopy Using an Optical Frequency Comb. In: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC): . Paper presented at Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), JUN 25-29, 2017, Munich, GERMANY. IEEE
Open this publication in new window or tab >>Faraday Rotation Spectroscopy Using an Optical Frequency Comb
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2017 (English)In: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC), IEEE, 2017Conference paper, Published 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.

Place, publisher, year, edition, pages
IEEE, 2017
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-152153 (URN)10.1109/CLEOE-EQEC.2017.8086909 (DOI)000432564600668 ()978-1-5090-6736-7 (ISBN)
Conference
Conference on Lasers and Electro-Optics Europe / European Quantum Electronics Conference (CLEO/Europe-EQEC), JUN 25-29, 2017, Munich, GERMANY
Funder
Swedish Foundation for Strategic Research , ICA12-0031Knut and Alice Wallenberg Foundation, KAW 2015.0159
Available from: 2018-10-01 Created: 2018-10-01 Last updated: 2018-10-01Bibliographically approved
Khodabakhsh, A. (2017). Fourier transform and Vernier spectroscopy using optical frequency combs. (Doctoral dissertation). Umeå: Umeå University
Open this publication in new window or tab >>Fourier transform and Vernier spectroscopy using optical frequency combs
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Fouriertransform- och Vernierspektroskopi med optiska frekvenskammar
Abstract [en]

Optical frequency comb spectroscopy (OFCS) combines two previously exclusive features, i.e., wide optical bandwidth and high spectral resolution, enabling precise measurements of entire molecular bands and simultaneous monitoring of multiple gas species in a short measurement time. Moreover, the equidistant mode structure of frequency combs enables efficient coupling of the comb power to enhancement resonant cavities, yielding high detection sensitivities. Different broadband detection methods have been developed to exploit the full potential of frequency combs in spectroscopy, based either on Fourier transform spectroscopy or on dispersive elements.There have been two main aims of the research presented in this thesis. The first has been to improve the performance of mechanical Fourier transform spectrometers (FTS) based on frequency combs in terms of sensitivity, resolution and spectral coverage. In pursuit of this aim, we have developed a new spectroscopic technique, so-called noise-immune cavity-enhanced optical frequency comb spectroscopy (NICE-OFCS), and achieved a shot-noise-limited sensitivity and low ppb (parts-per-billion, 10−9) CO2 concentration detection limit in the near-infrared range using commercially available components. We have also realized a novel method for acquisition and analysis of comb-based FTS spectra, a so-called sub-nominal resolution method, which provides ultra-high spectral resolution and frequency accuracy (both in kHz range, limited only by the stability of the comb) over the broadband spectral range of the frequency comb. Finally, we have developed an optical parametric oscillator generating a frequency comb in the mid-infrared range, where the strongest ro-vibrational molecular absorption lines reside. Using this mid-infrared comb and an FTS, we have demonstrated, for the first time, comb spectroscopy above 5 μm, measured broadband spectra of several species and reached low ppb detection limits for CH4, NO and CO in 1 s.The second aim has been more application-oriented, focused on frequency comb spectroscopy in combustion environments and under atmospheric conditions for fast and sensitive multispecies detection. We have demonstrated, for the first time, cavity-enhanced optical frequency comb spectroscopy in a flame, detected broadband high temperature H2O and OH spectra using the FTS in the near-infrared range and showed the potential of the technique for flame thermometry. For applications demanding a short measurement time and high sensitivity under atmospheric pressure conditions, we have implemented continuous-filtering Vernier spectroscopy, a dispersion-based spectroscopic technique, for the first time in the mid-infrared range. The spectrometer was sensitive, fast, robust, and capable of multispecies detection with 2 ppb detection limit for CH4 in 25 ms.

Abstract [sv]

Optisk frekvenskamspektroskopi (OFCS) kombinerar två tidigare icke förenliga egenskaper, dvs. ett brett optiskt frekvensområde med en hög spektral upplösning, vilket möjliggör noggranna mätningar av hela molekylära absorptionsband och detektion av flera gaser samtidigt med en kort mättid. Eftersom frekvenskammar har en regelbunden struktur med jämnt separerade laser moder kan man effektivt koppla kammen till en optisk kavitet och därmed möjliggöra frekvenskamsdetektion med hög känslighet. Olika metoder har utvecklats för att utnyttja frekvenskammarnas fulla potential för spektroskopi, baserad på antingen Fouriertransform-spektroskopi eller dispersiva element.Forskningen som presenteras i denna avhandling har haft två huvudmål. Det första har varit att förbättra prestandan hos mekaniska Fourier-transformspektrometrar (FTS) baserat på frekvenskammar med avseende på känslighet, upplösning och spektral täckning. I strävan efter detta har vi utvecklat en ny spektroskopisk teknik, benämnd brusimmun kavitetsförstärkt optisk frekvenskamspektroskopi (NICE-OFCS), och uppnått en hagelbrusbegränsad känslighet och detektionsgränser ner till låga ppb koncentrationer (miljarddelar, 10−9) för CO2 i det när-infraröda frekvensområdet enbart med användning av kommersiellt tillgängliga komponenter. Vi har också utvecklat en ny metod för insamling och analys av kambaserade FTS-spektra, som betecknas ha sub-nominell upplösning. Metoden gör det möjligt att uppnå ultrahög spektral upplösning och hög frekvensnoggrannhet (båda i kHz-området, endast begränsad av kammens stabilitet) över kammens hela frekvensområde. Slutligen har vi utvecklat en optisk parametrisk oscillator som genererar en frekvenskam i det mid-infraröda frekvensområdet, där de starkaste rotations-vibrationsmolekylära absorptionslinjerna finns. Med hjälp av denna kam och en FTS har vi för första gången demonstrerat frekvenskamspektroskopi över 5 μm. Vi har detekterat bredbandsspektra av flera molekylära gaser och har, för mättider på 1 s, uppnått detektionsgränser ner till låga ppb halter för CH4, NO och CO.Det andra syftet har varit mer applikationsorienterat: att använda frekvenskamspektroskopi i förbränningsmiljö och under atmosfäriska förhållanden för snabb och känslig multiämnesdetektion. Vi har för första gången demonstrerat kavitetsförstärkt optisk frekvenskamspektroskopi i en flamma, där vi har detekterat högtemperaturspektra av H2O och OH i det när-infraröda området med användning av FTS och visat teknikens potential för termometrisk karakterisering av flammor. För applikationer som kräver en kort mättid och hög känslighet under atmosfäriska förhållanden har vi utvecklat ett detektionssystem baserat på Vernier-spektroskopi med kontinuerlig filtrering, vilket är en dispersionsbaserad teknik, för första gången i det mid-infraröda frekvensområdet. Det befanns att spektrometern var känslig, snabb, robust och kapabel till multiämnesdetektion med en detektionsgräns på 2 ppb för CH4 för korta mättider (25 ms).

Place, publisher, year, edition, pages
Umeå: Umeå University, 2017. p. 164
Keywords
optical frequency comb spectroscopy, molecular absorption, resonant cavity, Fourier transform spectroscopy, Vernier spectroscopy
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:umu:diva-134439 (URN)978-91-7601-671-8 (ISBN)
Public defence
2017-06-02, KB.E3.03, Stora Hörsalen, KBC building, Umeå, 13:15 (English)
Opponent
Supervisors
Available from: 2017-05-12 Created: 2017-05-07 Last updated: 2018-06-09Bibliographically approved
Rutkowski, L., Johansson, A. C., Khodabakhsh, A. & Foltynowicz, A. (2017). Mechanical Fourier Transform Spectrometer with kHz Resolution. In: 2017 conference on lasers and electro-optics (CLEO): Science and innovations. Paper presented at Conference on Lasers and Electro-Optics (CLEO), MAY 14-19, 2017, San Jose, CA. IEEE, Article ID SW4J.6.
Open this publication in new window or tab >>Mechanical Fourier Transform Spectrometer with kHz Resolution
2017 (English)In: 2017 conference on lasers and electro-optics (CLEO): Science and innovations, IEEE, 2017, article id SW4J.6Conference paper, Published paper (Refereed)
Abstract [en]

We measure simultaneously 11000 resonances of a high-finesse cavity with kHz level resolution using optical frequency comb Fourier transform spectroscopy and retrieve the dispersion of the cavity mirrors from the cavity mode spacing.

Place, publisher, year, edition, pages
IEEE, 2017
Series
Conference on Lasers and Electro-Optics, ISSN 2160-9020
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-146827 (URN)10.1364/CLEO_SI.2017.SW4J.6 (DOI)000427296203097 ()978-1-9435-8027-9 (ISBN)
Conference
Conference on Lasers and Electro-Optics (CLEO), MAY 14-19, 2017, San Jose, CA
Available from: 2018-04-23 Created: 2018-04-23 Last updated: 2018-06-09Bibliographically approved
Khodabakhsh, A., Rutkowski, L., Morville, J. & Foltynowicz, A. (2017). Mid-infrared continuous-filtering Vernier spectroscopy using a doubly resonant optical parametric oscillator. Applied physics. B, Lasers and optics (Print), 123(210)
Open this publication in new window or tab >>Mid-infrared continuous-filtering Vernier spectroscopy using a doubly resonant optical parametric oscillator
2017 (English)In: Applied physics. B, Lasers and optics (Print), ISSN 0946-2171, E-ISSN 1432-0649, Vol. 123, no 210Article in journal (Refereed) Published
Abstract [en]

We present a continuous-filtering Vernier spectrometer operating in the 3.15-3.4 mu m range, based on a femtosecond doubly resonant optical parametric oscillator, a cavity with a finesse of 340, a grating mounted on a galvo scanner, and two photodiodes. The spectrometer allows acquisition of one spectrum spanning 250 nm of bandwidth in 25 ms with 8 GHz resolution, sufficient to detect molecular lines at atmospheric pressure. An active lock ensures good frequency and intensity stability of the consecutive spectra and enables continuous signal acquisition and efficient averaging. The relative frequency scale is calibrated using a Fabry-Perot etalon or, alternatively, the galvo scanner position signal. We measure spectra of a calibrated CH4 gas sample as well as dry and laboratory air and extract CH4 and -H2O concentrations by multiline fitting of model spectra. The figure of merit of the spectrometer is 1.7 x 10(-9) cm(-1) Hz(-1/2) per spectral element and the minimum detectable concentration of CH4 is 360 ppt Hz(-1/2), averaging down to 90 ppt after 16 s.

National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-134435 (URN)000405506200015 ()
Available from: 2017-05-07 Created: 2017-05-07 Last updated: 2018-06-09Bibliographically approved
Maslowski, P., Kowzan, G., Charczun, D., Lisak, D., Trawinski, R., Rutkowski, L., . . . Fermann, M. E. (2017). Optical Frequency Comb Spectroscopy for Gas Metrology and Trace Gas Detection. In: 2017 Conference on lasers and electro-optics (CLEO): . Paper presented at Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, MAY 14-19, 2017. IEEE
Open this publication in new window or tab >>Optical Frequency Comb Spectroscopy for Gas Metrology and Trace Gas Detection
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2017 (English)In: 2017 Conference on lasers and electro-optics (CLEO), IEEE, 2017Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

We report recent developments of comb-based broadband absorption spectroscopy. The comb-line resolving approaches and Fourier transform spectroscopy with sub-nominal resolution overcome the frequency resolution limits of conventional techniques. Advantages for various applications will be discussed.

Place, publisher, year, edition, pages
IEEE, 2017
Series
Conference on Lasers and Electro-Optics, ISSN 2160-9020
Keywords
Spectroscopy: 300.6320 Spectroscopy, high-resolution, Spectroscopy: 300.1030 Absorption, ectroscopy: 300.6300 Spectroscopy, Fourier transforms
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-146825 (URN)000427296203096 ()978-1-9435-8027-9 (ISBN)978-1-5386-2019-9 (ISBN)
Conference
Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, MAY 14-19, 2017
Available from: 2018-04-20 Created: 2018-04-20 Last updated: 2018-06-09Bibliographically approved
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