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Wichmann G, Miloglyadov E, Seyfang G, Quack M. Nuclear spin symmetry conservation studied by cavity ring-down spectroscopy of ammonia in a seeded supersonic jet from a pulsed slit nozzle. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1752946] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- G. Wichmann
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - E. Miloglyadov
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - G. Seyfang
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - M. Quack
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
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Alahmari S, Kang XW, Hippler M. Diode laser photoacoustic spectroscopy of CO 2, H 2S and O 2 in a differential Helmholtz resonator for trace gas analysis in the biosciences and petrochemistry. Anal Bioanal Chem 2019; 411:3777-3787. [PMID: 31111181 PMCID: PMC6595070 DOI: 10.1007/s00216-019-01877-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/16/2019] [Accepted: 04/26/2019] [Indexed: 11/29/2022]
Abstract
Photoacoustic spectroscopy in a differential Helmholtz resonator has been employed with near-IR and red diode lasers for the detection of CO2, H2S and O2 in 1 bar of air/N2 and natural gas, in static and flow cell measurements. With the red distributed feedback (DFB) diode laser, O2 can be detected at 764.3 nm with a noise equivalent detection limit of 0.60 mbar (600 ppmv) in 1 bar of air (35-mW laser, 1-s integration), corresponding to a normalised absorption coefficient α = 2.2 × 10-8 cm-1 W s1/2. Within the tuning range of the near-IR DFB diode laser (6357-6378 cm-1), CO2 and H2S absorption features can be accessed, with a noise equivalent detection limit of 0.160 mbar (160 ppmv) CO2 in 1 bar N2 (30-mW laser, 1-s integration), corresponding to a normalised absorption coefficient α = 8.3 × 10-9 cm-1 W s1/2. Due to stronger absorptions, the noise equivalent detection limit of H2S in 1 bar N2 is 0.022 mbar (22 ppmv) at 1-s integration time. Similar detection limits apply to trace impurities in 1 bar natural gas. Detection limits scale linearly with laser power and with the square root of integration time. At 16-s total measurement time to obtain a spectrum, a noise equivalent detection limit of 40 ppmv CO2 is obtained after a spectral line fitting procedure, for example. Possible interferences due to weak water and methane absorptions have been discussed and shown to be either negligible or easy to correct. The setup has been used for simultaneous in situ monitoring of O2, CO2 and H2S in the cysteine metabolism of microbes (E. coli), and for the analysis of CO2 and H2S impurities in natural gas. Due to the inherent signal amplification and noise cancellation, photoacoustic spectroscopy in a differential Helmholtz resonator has a great potential for trace gas analysis, with possible applications including safety monitoring of toxic gases and applications in the biosciences and for natural gas analysis in petrochemistry. Graphical abstract.
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Affiliation(s)
- Saeed Alahmari
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK
| | - Xiu-Wen Kang
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK
| | - Michael Hippler
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK.
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Manca Tanner C, Quack M, Schmidiger D. Nuclear spin symmetry conservation and relaxation of water (H216O) seeded in supersonic jets of argon and oxygen: measurements by cavity ring-down laser spectroscopy. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1484952] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
| | - Martin Quack
- Laboratorium für Physikalische Chemie, ETH Zürich, Zürich, Switzerland
| | - David Schmidiger
- Laboratorium für Physikalische Chemie, ETH Zürich, Zürich, Switzerland
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Chen TL, Liu YW. Sub-Doppler resolution near-infrared spectroscopy at 1.28 μm with the noise-immune cavity-enhanced optical heterodyne molecular spectroscopy method. OPTICS LETTERS 2017; 42:2447-2450. [PMID: 28957256 DOI: 10.1364/ol.42.002447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 06/01/2017] [Indexed: 06/07/2023]
Abstract
We report on the sub-Doppler saturation spectroscopy of the nitrous oxide (N2O) overtone transition at 1.28 μm. This measurement is performed by the noise-immune cavity-enhanced optical heterodyne molecular spectroscopy technique based on the quantum-dot (QD) laser. A high intra-cavity power, up to 10 W, reaches the saturation limit of the overtone line using an optical cavity with a high finesse of 1.14(5)×105. At a pressure of several mTorr, the saturation dip is observed with a full width at half-maximum of about 2 MHz and a signal-to-noise ratio of 71. To the best of our knowledge, this is the first saturation spectroscopy of molecular overtone transitions in the 1.3 μm region. The QD laser is then locked to this dispersion signal with a stability of 15 kHz at 1 s integration time. We demonstrate the potential of the N2O as a marker because of its particularly rich spectrum at the vicinity of 1.28-1.30 μm where there are several important forbidden transitions of atomic parity violation measurements and the 1.3 μm O-band of optical communication.
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Tanner CM, Quack M. Reinvestigation of the ν2 + 2ν3subband in the overtone icosad of12CH4using cavity ring-down (CRD) spectroscopy of a supersonic jet expansion. Mol Phys 2012. [DOI: 10.1080/00268976.2012.702934] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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8
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Votava O, Mašát M, Parker AE, Jain C, Fittschen C. Microcontroller based resonance tracking unit for time resolved continuous wave cavity-ringdown spectroscopy measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:043110. [PMID: 22559518 DOI: 10.1063/1.3698061] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present in this work a new tracking servoloop electronics for continuous wave cavity-ringdown absorption spectroscopy (cw-CRDS) and its application to time resolved cw-CRDS measurements by coupling the system with a pulsed laser photolysis set-up. The tracking unit significantly increases the repetition rate of the CRDS events and thus improves effective time resolution (and/or the signal-to-noise ratio) in kinetics studies with cw-CRDS in given data acquisition time. The tracking servoloop uses novel strategy to track the cavity resonances that result in a fast relocking (few ms) after the loss of tracking due to an external disturbance. The microcontroller based design is highly flexible and thus advanced tracking strategies are easy to implement by the firmware modification without the need to modify the hardware. We believe that the performance of many existing cw-CRDS experiments, not only time-resolved, can be improved with such tracking unit without any additional modification to the experiment.
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Affiliation(s)
- Ondrej Votava
- Academy of Sciences of the Czech Republic, J. Heyrovský Institute of Physical Chemistry, Dolejškova 2155/3 18223 Prague 8, Czech Republic.
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Hippler M, Mohr C, Keen KA, McNaghten ED. Cavity-enhanced resonant photoacoustic spectroscopy with optical feedback cw diode lasers: A novel technique for ultratrace gas analysis and high-resolution spectroscopy. J Chem Phys 2010; 133:044308. [PMID: 20687651 DOI: 10.1063/1.3461061] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cavity-enhanced resonant photoacoustic spectroscopy with optical feedback cw diode lasers (OF-CERPAS) is introduced as a novel technique for ultratrace gas analysis and high-resolution spectroscopy. In the scheme, a single-mode cw diode laser (3 mW, 635 nm) is coupled into a high-finesse linear cavity and stabilized to the cavity by optical feedback. Inside the cavity, a build-up of laser power to at least 2.5 W occurs. Absorbing gas phase species inside the cavity are detected with high sensitivity by the photoacoustic effect using a microphone embedded in the cavity. To increase sensitivity further, coupling into the cavity is modulated at a frequency corresponding to a longitudinal resonance of an organ pipe acoustic resonator (f=1.35 kHz and Q approximately 10). The technique has been characterized by measuring very weak water overtone transitions near 635 nm. Normalized noise-equivalent absorption coefficients are determined as alpha approximately 4.4x10(-9) cm(-1) s(1/2) (1 s integration time) and 2.6x10(-11) cm(-1) s(1/2) W (1 s integration time and 1 W laser power). These sensitivities compare favorably with existing state-of-the-art techniques. As an advantage, OF-CERPAS is a "zero-background" method which increases selectivity and sensitivity, and its sensitivity scales with laser power.
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Affiliation(s)
- Michael Hippler
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom.
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Hippler M, Oeltjen L, Quack M. High-Resolution Continuous-Wave-Diode Laser Cavity Ring-Down Spectroscopy of the Hydrogen Fluoride Dimer in a Pulsed Slit Jet Expansion: Two Components of the N = 2 Triad near 1.3 μm. J Phys Chem A 2007; 111:12659-68. [DOI: 10.1021/jp076894s] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Michael Hippler
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland, and Department of Chemistry, University of Sheffield, Sheffield S3 7HF, England
| | - Lars Oeltjen
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland, and Department of Chemistry, University of Sheffield, Sheffield S3 7HF, England
| | - Martin Quack
- Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland, and Department of Chemistry, University of Sheffield, Sheffield S3 7HF, England
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Hippler M. Quantum chemical study and infrared spectroscopy of hydrogen-bonded CHCl3–NH3 in the gas phase. J Chem Phys 2007; 127:084306. [PMID: 17764247 DOI: 10.1063/1.2757176] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Molecular association of chloroform with ammonia is studied by high-level quantum chemical calculations including correlated MP2 and CCSD(T) calculations with basis sets up to6-311++G(d,p) and counterpoise corrected energies, geometries, and frequencies. The calculations predict an eclipsed hydrogen-bonded complex of C(3v) symmetry (DeltaE(0)=-15.07 kJ mol(-1)) with 225.4 pm intermolecular CHcdots, three dots, centeredN distance. Intermolecular interactions are analysed by Kitaura-Morokuma [Int. J. Quantum Chem. 10, 325 (1976)] interaction energy decomposition. Compared to the monomer, the C-H bond is elongated, and the CH-stretching fundamental shifts to lower wave numbers and has a marked approximately 340-fold increase of its intensity. Based on these predictions, the complex is observed by infrared spectroscopy in the gas phase at room temperature. A subtraction procedure isolates its spectrum, and a dilution series confirms the presence of a 1:1 complex. The CHCl(3)cdots, three dots, centeredNH(3) complex has an experimental -17.5 cm(-1) shift of its CH-stretching vibration, and CDCl(3)cdots, three dots, centeredNH(3) a -12.5 cm(-1) shift of the CD-stretching vibration. After a deperturbation of the CH-stretching/bending mode Fermi resonance system, this indicates a "redshifting" or more appropriately, a "C-H elongating" hydrogen bond in agreement with the ab initio calculations. An estimate of the complex concentration gives the equilibrium constant K(p)=0.024 (p(theta)=10(5) Pa) at 295 K for the dimerization, providing one of the few examples where a hydrogen-bonded gas phase complex at room temperature could be quantitatively studied by infrared spectroscopy.
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Affiliation(s)
- Michael Hippler
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom.
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He Y, Orr BJ. Continuous-wave cavity ringdown absorption spectroscopy with a swept-frequency laser: rapid spectral sensing of gas-phase molecules. APPLIED OPTICS 2005; 44:6752-61. [PMID: 16270564 DOI: 10.1364/ao.44.006752] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A cavity ringdown spectrometer, based on a continuous-wave swept-frequency laser, enables efficient, rapid recording of wide-ranging absorption spectra as characteristic spectral signatures of airborne molecules. The rapidly swept laser frequency resonates with the longitudinal modes of the ringdown cavity, effectively sampling the absorption spectrum of an intracavity gas at intervals defined by the cavity's free spectral range and generating a full absorption spectrum within a single rapid sweep of the widely tunable laser frequency. We report a new analog detection scheme that registers a single data point for each buildup and ringdown decay event without logging details of the full signal waveform; this minimizes demand on digitizer speed and memory depth, reducing the time scale of data processing. This results in a compact, robust, easy-to-use instrument that offers fresh prospects for spectroscopic sensing of trace species in the atmosphere.
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Affiliation(s)
- Yabai He
- Centre for Lasers and Applications, Macquarie University, Sydney, New South Wales 2109, Australia
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14
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Dupré P, Gherman T, Zobov NF, Tolchenov RN, Tennyson J. Continuous-wave cavity ringdown spectroscopy of the 8ν polyad of water in the 25195−25340cm−1 range. J Chem Phys 2005; 123:154307. [PMID: 16252948 DOI: 10.1063/1.2055247] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
State-of-the-art experiments and calculations are used to record and assign the data obtained in the weakly absorbing blue energy region of the H2O spectrum. Continuous-wave cavity ringdown absorption spectroscopy with Doppler resolution is used to probe the range from 25,195 to 25,470 cm(-1) with an absorption sensitivity of approximately 1 parts per 10(9) (ppb)/cm. 62 lines of the polyad nu(OH)=8 are reported, of which 43 are assigned using variational nuclear calculations. The study includes absorption line intensities (in the range of 10(-28)-10(-26) cmmolecule) for all lines and self-broadening pressure coefficient for a few lines. The newly obtained energy levels are also reported.
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Affiliation(s)
- Patrick Dupré
- Laboratoire de Spectrométrie Physique [associated with Centre National de la Recherche Scientifique (CNRS) Unite Mixte de Recherche (UMR) C5588], Université Joseph Fourier de Grenoble, Saint-Martin d'Hères Cedex, France.
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15
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Sharma RC, Huang HY, Chuang WT, Lin KC. Continuum and discrete pulsed cavity ring down laser absorption spectra of Br2 vapor. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2005; 61:2115-20. [PMID: 15911400 DOI: 10.1016/j.saa.2004.08.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Accepted: 08/19/2004] [Indexed: 05/02/2023]
Abstract
The absorption cross-sections at room temperature are reported for the first time, of Br2 vapor in overlapping bound-free and bound-bound transition of A(3)pi1u <-- Xsigma(g)+, X(1)pi1u <-- X(1)sigma(g)+ and B(3)pi0u <-- X(1)sigma(g)+, using cavity ring down spectroscopy (CRDS) technique. We reported here, the A(3)pi1u <-- X(1)sigma(g)+, transition is included along with the two stronger X(1)pi1u <-- X(1)sigma(g)+ and B(3)pi0u <-- X(1)sigma(g) transitions of Br2. We obtained discrete absorption cross-section in the rotational structure, the continuum absorption cross-sections, and were also able to measure the absorption cross-section in separate contribution of A(3)pi1u <-- X(1)sigma(g)+, (1)pi1u <-- X(1)sigma(g)+, and B(3)pi0u <-- X(1)sigma(g)+ transitions using CRDS method to use quantum yield of Br*((2)P(1/2)). We obtained absorption cross-section order 10(-19) cm2 and detection 10(13) molecule cm(-3) (1 mTorr) of Br2. The absorption cross-sections are increasing with increasing excitation energy in the wavelength region 510-535 nm.
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Affiliation(s)
- Ramesh C Sharma
- Laser Chemical Physics Laboratory, Engineering Faculty, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
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Mazurenka M, Orr-Ewing AJ, Peverall R, Ritchie GAD. 4 Cavity ring-down and cavity enhanced spectroscopy using diode lasers. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b408909j] [Citation(s) in RCA: 201] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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17
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Phase shift cavity ring down and FT-VIS measurements of C–H (Δv=5) vibrational overtone absorptions. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.06.102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Affiliation(s)
- Stephen M Ball
- University Chemical Laboratory, Cambridge University, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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Mazurenka MI, Fawcett BL, Elks JM, Shallcross DE, Orr-Ewing AJ. 410-nm diode laser cavity ring-down spectroscopy for trace detection of NO2. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(02)01652-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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21
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Birza P, Motylewski T, Khoroshev D, Chirokolava A, Linnartz H, Maier J. Cw cavity ring down spectroscopy in a pulsed planar plasma expansion. Chem Phys 2002. [DOI: 10.1016/s0301-0104(02)00503-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Atkinson DB, Spillman JL. Alkyl Peroxy Radical Kinetics Measured Using Near-infrared CW−Cavity Ring-down Spectroscopy. J Phys Chem A 2002. [DOI: 10.1021/jp0257597] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Dean B. Atkinson
- Department of Chemistry, Portland State University, Portland, Oregon 97207-0751
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23
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Hippler M, Quack M. High-resolution Fourier transform infrared and cw-diode laser cavity ringdown spectroscopy of the ν2+2ν3 band of methane near 7510 cm−1 in slit jet expansions and at room temperature. J Chem Phys 2002. [DOI: 10.1063/1.1433505] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Łapiński A, Spanget-Larsen J, Waluk J, Radziszewski JG. Vibrations of nitrous oxide: Matrix isolation Fourier transform infrared spectroscopy of twelve N2O isotopomers. J Chem Phys 2001. [DOI: 10.1063/1.1383031] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Lewis EK, Reynolds D, Li X, de Villele G, Leduc C, Cedeño DL, Manzanares I C. Phase shift cavity ring-down measurement of C–H (Δv=6) vibrational overtone absorptions. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(00)01466-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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26
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He Y, Orr BJ. Optical heterodyne signal generation and detection in cavity ringdown spectroscopy based on a rapidly swept cavity. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)00031-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Bucher CR, Lehmann KK, Plusquellic DF, Fraser GT. Doppler-free nonlinear absorption in ethylene by use of continuous-wave cavity ringdown spectroscopy. APPLIED OPTICS 2000; 39:3154-3164. [PMID: 18345246 DOI: 10.1364/ao.39.003154] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report what we believe to be the first systematic study of Doppler-free, nonlinear absorption by use of cavity ringdown spectroscopy. We have developed a variant of cavity ringdown spectroscopy for the mid-infrared region between 9 and 11 microm, exploiting the intracavity power buildup that is possible with continuous-wave lasers. The infrared source consists of a continuous-wave CO2 laser with 1-mW tunable infrared sidebands that couple into a high-finesse stable resonator. We tune the sideband frequencies to observe a saturated, Doppler-free Lamb dip in the nu7, 11(1,10) <-- 11(2,10) rovibrational transition of ethylene (C2H4). Power studies of the Lamb dip are presented to examine the intracavity effects of saturation on the Lamb-dip linewidth, the peak depth, and the broadband absorption.
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Affiliation(s)
- C R Bucher
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
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Totschnig G, Baer DS, Wang J, Winter F, Hofbauer H, Hanson RK. Multiplexed continuous-wave diode-laser cavity ringdown measurements of multiple species. APPLIED OPTICS 2000; 39:2009-2016. [PMID: 18345101 DOI: 10.1364/ao.39.002009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Rapid cavity ringdown measurements of multiple broadband absorbing species (methanol and isopropanol) in gas mixtures have been recorded with two multiplexed continuous-wave distributed-feedback diode lasers operating near 1.4 mum. A measurement sensitivity of 2.4 x 10(-9) cm(-1) for a 4.3-s averaging time was achieved in a 39.5-cm-long static cell with 99.94% reflectivity mirrors. This corresponds to a water-vapor detection limit of less than 2 ppb (parts in 10(9)) for the strong H(2)O lines near 1.4 mum. The shot-to-shot noise of the decay time constant tau was approximately 0.3-0.7%, and ringdown acquisition rates as great as 900 Hz were achieved.
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Affiliation(s)
- G Totschnig
- High Temperature Gasdynamics Laboratory, Department of Mechanical Engineering, Stanford University, Stanford, California 94305, USA.
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29
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Ringdown and cavity-enhanced absorption spectroscopy using a continuous-wave tunable diode laser and a rapidly swept optical cavity. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00107-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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30
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Hippler M, Quack M. Cw cavity ring-down infrared absorption spectroscopy in pulsed supersonic jets: nitrous oxide and methane. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)01071-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Oshika H, Toba A, Fujitake M, Ohashi N. Newly Observed Vibrotational Bands of N(2)O in 1.3-µm Region. JOURNAL OF MOLECULAR SPECTROSCOPY 1999; 197:324-325. [PMID: 10479598 DOI: 10.1006/jmsp.1999.7922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- H Oshika
- Faculty of Science, Kanazawa University, Kanazawa, Kakuma-machi, 920-1192, Japan
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