umu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Abd Alrahman, Chadi
Alternative names
Publications (3 of 3) Show all publications
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
Open this publication in new window or tab >>Cavity-enhanced optical frequency comb spectroscopy of high-temperature H2O in a flame
Show others...
2014 (English)In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 22, no 11, p. 13889-13895Article in journal (Refereed) 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.

National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-91203 (URN)10.1364/OE.22.013889 (DOI)000337501600113 ()
Available from: 2014-07-23 Created: 2014-07-21 Last updated: 2018-06-07Bibliographically approved
Khodabakhsh, A., Abd Alrahman, C. & Foltynowicz, A. (2014). Noise-immune cavity-enhanced optical frequency comb spectroscopy. Optics Letters, 39(17), 5034-5037
Open this publication in new window or tab >>Noise-immune cavity-enhanced optical frequency comb spectroscopy
2014 (English)In: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 39, no 17, p. 5034-5037Article in journal (Refereed) 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.

Place, publisher, year, edition, pages
Optical Society of America, 2014
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:umu:diva-94151 (URN)10.1364/OL.39.005034 (DOI)000341100300016 ()25166067 (PubMedID)
Available from: 2014-10-08 Created: 2014-10-06 Last updated: 2018-06-07Bibliographically approved
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
Open this publication in new window or tab >>Note: Simple and compact piezoelectric mirror actuator with 100 kHz bandwidth, using standard components
2013 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 84, no 5, p. 056112-Article in journal (Refereed) 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.

National Category
Accelerator Physics and Instrumentation
Identifiers
urn:nbn:se:umu:diva-76813 (URN)10.1063/1.4807859 (DOI)000319999300086 ()
Available from: 2013-07-16 Created: 2013-07-15 Last updated: 2018-06-08Bibliographically approved
Organisations

Search in DiVA

Show all publications