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Abd Alrahman, Chadi
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Abd Alrahman, C., Khodabakhsh, A., Schmidt, F. M., Qu, Z. & Foltynowicz, A. (2014). Cavity-enhanced optical frequency comb spectroscopy of high-temperature H2O in a flame. Optics Express, 22(11), 13889-13895
Öppna denna publikation i ny flik eller fönster >>Cavity-enhanced optical frequency comb spectroscopy of high-temperature H2O in a flame
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2014 (Engelska)Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 22, nr 11, s. 13889-13895Artikel i tidskrift (Refereegranskat) Published
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.

Nationell ämneskategori
Atom- och molekylfysik och optik
Identifikatorer
urn:nbn:se:umu:diva-91203 (URN)10.1364/OE.22.013889 (DOI)000337501600113 ()
Tillgänglig från: 2014-07-23 Skapad: 2014-07-21 Senast uppdaterad: 2018-06-07Bibliografiskt granskad
Khodabakhsh, A., Abd Alrahman, C. & Foltynowicz, A. (2014). Noise-immune cavity-enhanced optical frequency comb spectroscopy. Optics Letters, 39(17), 5034-5037
Öppna denna publikation i ny flik eller fönster >>Noise-immune cavity-enhanced optical frequency comb spectroscopy
2014 (Engelska)Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 39, nr 17, s. 5034-5037Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

We present a new method of optical frequency comb spectroscopy that combines cavity enhancement with frequency modulation to obtain immunity to laser frequency-to-amplitude noise conversion by the cavity modes and, thus, high absorption sensitivity over a broad spectral range. A frequency comb is locked to a cavity with a free spectral range (FSR) equal to 4/3 times the repetition rate of the laser, and phase-modulated at a frequency equal to the cavity FSR. The transmitted light is analyzed by a Fourier transform spectrometer with a high bandwidth detector. Phase-sensitive detection of the interferogram yields a noise-immune cavity-enhanced optical frequency comb spectroscopy (NICE-OFCS) signal. In the first demonstration, we record NICE-OFCS signals from the overtone CO2 band at 1575 nm with absorption sensitivity of 4.3 x 10(-10) cm(-1) Hz(-1/2) per spectral element, close to the shot noise limit.

Ort, förlag, år, upplaga, sidor
Optical Society of America, 2014
Nationell ämneskategori
Atom- och molekylfysik och optik
Identifikatorer
urn:nbn:se:umu:diva-94151 (URN)10.1364/OL.39.005034 (DOI)000341100300016 ()25166067 (PubMedID)
Tillgänglig från: 2014-10-08 Skapad: 2014-10-06 Senast uppdaterad: 2018-06-07Bibliografiskt granskad
Chadi, A. A., Mejean, G., Grilli, R. & Romanini, D. (2013). Note: Simple and compact piezoelectric mirror actuator with 100 kHz bandwidth, using standard components. Review of Scientific Instruments, 84(5), 056112
Öppna denna publikation i ny flik eller fönster >>Note: Simple and compact piezoelectric mirror actuator with 100 kHz bandwidth, using standard components
2013 (Engelska)Ingår i: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 84, nr 5, s. 056112-Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

We propose a mounting scheme to control the displacement of a mirror (or other small object) by a cylindrical piezoelectric actuator, giving uniform response and no phase lag up to high frequencies. This requires a simple ring holder, and unmodified off-the-shelf components. In our implementation, the piezo-mirror assembly has its first mechanical resonance around 120 kHz, close to the resonance for the bare piezo. The idea is to decouple the fundamental elongation mode of the piezo-mirror assembly from the holder by side-clamping the assembly at its zero-displacement plane for this mode. The main drawback is a reduced mirror displacement, by a factor 2 in our case (mirror displacement is similar to 2.5 mu m). Also, the mirror needs to be light with respect to the piezo: still, we use a standard half-inch mirror. The resulting system is very compact as it fits inside a 1-in. commercial steering mirror post.

Nationell ämneskategori
Acceleratorfysik och instrumentering
Identifikatorer
urn:nbn:se:umu:diva-76813 (URN)10.1063/1.4807859 (DOI)000319999300086 ()
Tillgänglig från: 2013-07-16 Skapad: 2013-07-15 Senast uppdaterad: 2018-06-08Bibliografiskt granskad
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