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Wilmouth DM, Sayres DS. Rayleigh scattering cross sections of argon, carbon dioxide, sulfur hexafluoride, and methane in the UV-A region using Broadband Cavity Enhanced Spectroscopy. JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER 2019; 234:32-39. [PMID: 31631911 PMCID: PMC6800691 DOI: 10.1016/j.jqsrt.2019.05.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Accurate Rayleigh scattering cross sections are important for understanding the propagation of electromagnetic radiation in planetary atmospheres and for calibrating mirror reflectivity in high finesse optical cavities. In this study, we used Broadband Cavity Enhanced Spectroscopy (BBCES) to measure Rayleigh scattering cross sections for argon, carbon dioxide, sulfur hexafluoride, and methane between 333 and 363 nm, extending the region of available UV measurements for all four gases. Comparison of our results with refractive index based (n-based) calculations demonstrates excellent agreement for Ar and CO2, within 0.2% and 1.0% on average, respectively. For SF6, our mean Rayleigh scattering cross sections are lower by 2.2% on average relative to the n-based calculation and lie outside the 1-σ measurement uncertainty; however, the results still fall within our 2-σ uncertainty. The measured Rayleigh scattering cross sections for CH4 are in substantial disagreement (22%) with those calculated from the most recent n-based values in the literature and lie far outside our mean 1-σ uncertainty of 1.6%. Extrapolation of several older index of refraction measurements from visible wavelengths to the UV yields better agreement with our results for CH4, but the agreement is still generally outside our 1-σ measurement uncertainty. Use of the dispersion relation derived in this work provides significantly improved Rayleigh scattering cross sections for CH4 in the UV-A spectral region.
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Fang B, Zhao W, Xu X, Zhou J, Ma X, Wang S, Zhang W, Venables DS, Chen W. Portable broadband cavity-enhanced spectrometer utilizing Kalman filtering: application to real-time, in situ monitoring of glyoxal and nitrogen dioxide. OPTICS EXPRESS 2017; 25:26910-26922. [PMID: 29092174 DOI: 10.1364/oe.25.026910] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 10/17/2017] [Indexed: 06/07/2023]
Abstract
This article describes the development and field application of a portable broadband cavity enhanced spectrometer (BBCES) operating in the spectral range of 440-480 nm for sensitive, real-time, in situ measurement of ambient glyoxal (CHOCHO) and nitrogen dioxide (NO2). The instrument utilized a custom cage system in which the same SMA collimators were used in the transmitter and receiver units for coupling the LED light into the cavity and collecting the light transmitted through the cavity. This configuration realised a compact and stable optical system that could be easily aligned. The dimensions and mass of the optical layer were 676 × 74 × 86 mm3 and 4.5 kg, respectively. The cavity base length was about 42 cm. The mirror reflectivity at λ = 460 nm was determined to be 0.9998, giving an effective absorption pathlength of 2.26 km. The demonstrated measurement precisions (1σ) over 60 s were 28 and 50 pptv for CHOCHO and NO2 and the respective accuracies were 5% and 4%. By applying a Kalman adaptive filter to the retrieved concentrations, the measurement precisions of CHOCHO and NO2 were improved to 8 pptv and 40 pptv in 21 s.
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Zhao W, Xu X, Fang B, Zhang Q, Qian X, Wang S, Liu P, Zhang W, Wang Z, Liu D, Huang Y, Venables DS, Chen W. Development of an incoherent broad-band cavity-enhanced aerosol extinction spectrometer and its application to measurement of aerosol optical hygroscopicity. APPLIED OPTICS 2017; 56:E16-E22. [PMID: 28414337 DOI: 10.1364/ao.56.000e16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report on the development of a blue light-emitting-diode-based incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for the measurement of the aerosol extinction coefficient at λ=461 nm. With an effective absorption path length of 2.8 km, an optimum detection limit of 0.05 Mm-1 (5×10-10 cm-1) was achieved with an averaging time of 84 s. The baseline drift of the developed spectrometer was about ±0.3 Mm-1 over 2.5 h (1σ standard deviation). The performance of the system was evaluated with laboratory-generated monodispersed polystyrene latex (PSL) spheres. The retrieved complex refractive index of PSL agreed well with previously reported values. The relative humidity (RH) dependence of the aerosol extinction coefficient was measured using IBBCEAS. The measured extinction enhancement factor values for 200 nm dry ammonium sulphate particles at different RH were in good agreement with the modeled values. Field performance of the aerosol extinction spectrometer was demonstrated at the Hefei Radiation Observatory site.
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Cui H, Li B, Han Y, Wang J, Gao C, Wang Y. Extinction measurement with open-path cavity ring-down technique of variable cavity length. OPTICS EXPRESS 2016; 24:13343-13350. [PMID: 27410351 DOI: 10.1364/oe.24.013343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Open-path cavity ring down (OPCRD) technique with variable cavity length was developed to measure optical extinction including scattering and absorption of air in laboratory environment at 635 nm wavelength. By moving the rear cavity mirror of the ring-down cavity to change cavity length, ring-down time with different cavity lengths was experimentally obtained and the dependence of total cavity loss on cavity length was determined. The extinction coefficient of air was determined by the slope of linear dependence of total cavity loss on cavity length. The extinction coefficients of air with different particle concentrations at 635 nm wavelength were measured to be from 10.46 to 84.19 Mm-1 (ppm/m) in a normal laboratory environment. This variable-cavity-length OPCRD technique can be used for absolute extinction measurement and real-time environmental monitoring without closed-path sample cells and background measurements.
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Lee B, Lehmann K, Taylor J, Yalin A. A high-finesse broadband optical cavity using calcium fluoride prism retroreflectors. OPTICS EXPRESS 2014; 22:11583-11591. [PMID: 24921279 DOI: 10.1364/oe.22.011583] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A high-finesse broadband optical cavity has been developed for use in the ultraviolet and visible region using Brewster-angle calcium fluoride (CaF₂) prism retroreflectors. Prior to prism construction, optical loss measurements of CaF₂ windows were performed using cavity ring-down spectroscopy at 250 nm. Total optical loss showed high spatial correlation with crystal birefringence, which was partially mitigated by orienting the <111> crystal axis with the laser beam. Prism reflectivity was measured using cavity ring-down spectroscopy and found to be 99.77% at 250 nm and 99.96% at 500 nm, allowing for relatively high-finesse operation over hundreds of nm bandwidth with a single cavity.
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Gu Z, Witschas B, van de Water W, Ubachs W. Rayleigh-Brillouin scattering profiles of air at different temperatures and pressures. APPLIED OPTICS 2013; 52:4640-4651. [PMID: 23842262 DOI: 10.1364/ao.52.004640] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 05/31/2013] [Indexed: 06/02/2023]
Abstract
Rayleigh-Brillouin (RB) scattering profiles for air have been recorded for the temperature range from 255 to 340 K and the pressure range from 640 to 3300 mbar, covering the conditions relevant for the Earth's atmosphere and for planned atmospheric light detection and ranging (LIDAR) missions. The measurements performed at a wavelength of λ=366.8 nm detect spontaneous RB scattering at a 90° scattering angle from a sensitive intracavity setup, delivering scattering profiles at a 1% rms noise level or better. The experimental results have been compared to a kinetic line-shape model, the acclaimed Tenti S6 model, considered to be most appropriate for such conditions, under the assumption that air can be treated as an effective single-component gas with temperature-scaled values for the relevant macroscopic transport coefficients. The elusive transport coefficient, the bulk viscosity η(b), is effectively derived by a comparing the measurements to the model, yielding an increased trend from 1.0 to 2.5×10(-5) kg·m(-1)·s(-1) for the temperature interval. The calculated (Tenti S6) line shapes are consistent with experimental data at the level of 2%, meeting the requirements for the future RB-scattering LIDAR missions in the Earth's atmosphere. However, the systematic 2% deviation may imply that the model has a limit to describe the finest details of RB scattering in air. Finally, it is demonstrated that the RB scattering data in combination with the Tenti S6 model can be used to retrieve the actual gas temperatures.
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Affiliation(s)
- Ziyu Gu
- LaserLaB, Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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Affiliation(s)
- Marcel Snels
- Istituto di Scienze dell’Atmosfera e del Clima (ISAC), Consiglio Nazionale delle Ricerche (CNR) , Rome, Italy
| | - Stefania Stefani
- Istituto di Astrofisica e Planetologia Spaziali (IAPS), Istituto Nazionale di AstroFisica (INAF) , Rome, Italy
| | - Giuseppe Piccioni
- Istituto di Astrofisica e Planetologia Spaziali (IAPS), Istituto Nazionale di AstroFisica (INAF) , Rome, Italy
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8
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Dong M, Zhao W, Huang M, Chen W, Hu C, Gu X, Pei S, Huang W, Zhang W. Near‐ultraviolet Incoherent Broadband Cavity Enhanced Absorption Spectroscopy for OClO and CH2O in Cl‐initiated Photooxidation Experiment. CHINESE J CHEM PHYS 2013. [DOI: 10.1063/1674-0068/26/02/133-139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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9
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Zhao W, Dong M, Chen W, Gu X, Hu C, Gao X, Huang W, Zhang W. Wavelength-Resolved Optical Extinction Measurements of Aerosols Using Broad-Band Cavity-Enhanced Absorption Spectroscopy over the Spectral Range of 445–480 nm. Anal Chem 2013; 85:2260-8. [DOI: 10.1021/ac303174n] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Weixiong Zhao
- Anhui Institute of Optics and
Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Meili Dong
- Anhui Institute of Optics and
Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Weidong Chen
- Laboratory of Physical Chemistry
of the Atmosphere, Université du Littoral Côte d’Opale, 189A Avenue Maurice Schumann, 59140
Dunkerque, France
| | - Xuejun Gu
- Anhui Institute of Optics and
Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Changjin Hu
- Anhui Institute of Optics and
Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Xiaoming Gao
- Anhui Institute of Optics and
Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Wei Huang
- Anhui Institute of Optics and
Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, Anhui, China
| | - Weijun Zhang
- Anhui Institute of Optics and
Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, Anhui, China
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10
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Long DA, Robichaud DJ, Hodges JT. Frequency-stabilized cavity ring-down spectroscopy measurements of line mixing and collision-induced absorption in the O2 A-band. J Chem Phys 2012; 137:014307. [DOI: 10.1063/1.4731290] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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11
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Kahan TF, Washenfelder RA, Vaida V, Brown SS. Cavity-enhanced measurements of hydrogen peroxide absorption cross sections from 353 to 410 nm. J Phys Chem A 2012; 116:5941-7. [PMID: 22225472 DOI: 10.1021/jp2104616] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report near-ultraviolet and visible absorption cross sections of hydrogen peroxide (H(2)O(2)) using incoherent broad-band cavity-enhanced absorption spectroscopy (IBBCEAS), a recently developed, high-sensitivity technique. The measurements reported here span the range of 353-410 nm and extend published electronic absorption cross sections by 60 nm to absorption cross sections below 1 × 10(-23) cm(2) molecule(-1). We have calculated photolysis rate constants for H(2)O(2) in the lower troposphere at a range of solar zenith angles by combining the new measurements with previously reported data at wavelengths shorter than 350 nm. We predict that photolysis at wavelengths longer than those included in the current JPL recommendation may account for up to 28% of the total hydroxyl radical (OH) production from H(2)O(2) photolysis under some conditions. Loss of H(2)O(2) via photolysis may be of the same order of magnitude as reaction with OH and dry deposition in the lower atmosphere; these processes have very different impacts on HO(x) loss and regeneration.
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Affiliation(s)
- Tara F Kahan
- Department of Chemistry and Biochemistry, University of Colorado, Campus Box 215, Boulder, Colorado 80309, United States
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12
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Spiering FR, van der Zande WJ. Collision induced absorption in the a1Δ(v = 2) ← X3Σ−g(v = 0) band of molecular oxygen. Phys Chem Chem Phys 2012; 14:9923-8. [DOI: 10.1039/c2cp40961e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Spiering FR, Kiseleva MB, Filippov NN, van Kesteren L, van der Zande WJ. Collision-induced absorption in the O2 B-band region near 670 nm. Phys Chem Chem Phys 2011; 13:9616-21. [DOI: 10.1039/c1cp20403c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Ponce-Marquez DM, Bray BD, Deterly TM, Liu C, Eldon D. Thomson scattering diagnostic upgrade on DIII-D. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2010; 81:10D525. [PMID: 21033880 DOI: 10.1063/1.3495759] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The DIII-D Thomson scattering system has been upgraded. A new data acquisition hardware was installed, adding the capacity for additional spatial channels and longer acquisition times for temperature and density measurements. Detector modules were replaced with faster transimpedance circuitry, increasing the signal-to-noise ratio by a factor of 2. This allows for future expansion to the edge system. A second phase upgrade scheduled for 2010-2011 includes the installation of four 1 J/pulse Nd:YAG lasers at 50 Hz repetition rate. This paper presents the first completed phase of the upgrade and performance comparison between the original system and the upgraded system. The plan for the second phase is also presented.
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Affiliation(s)
- D M Ponce-Marquez
- General Atomics, P.O. Box 85608, San Diego, California 092186-5608, USA.
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15
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Spiering FR, Kiseleva MB, Filippov NN, Naus H, van Lieshout B, Weijenborg C, van der Zande WJ. Line mixing and collision induced absorption in the oxygen A-band using cavity ring-down spectroscopy. J Chem Phys 2010; 133:114305. [PMID: 20866137 DOI: 10.1063/1.3460924] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This paper reports on the absorption of molecular oxygen in the region of the A-band near 760 nm under atmospheric conditions relevant for satellite retrieval studies. We use pulsed laser cavity ring-down spectroscopy with a narrow bandwidth laser and use pressure scans to increase the accuracy of the measured oxygen extinction coefficients. Absolute binary absorption coefficients in minima between absorption lines of the A-band spectrum have been measured and tabulated. We use the so-called adjustable branch coupling model including line mixing to calculate the magnetic dipole absorption in order to determine the contribution of collision induced absorption. The line mixing model has been optimized such that the collision induced absorption spectrum is smooth.
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Affiliation(s)
- Frans R Spiering
- Institute for Molecules and Matter, Radboud University, Nijmegen 6525AJ, The Netherlands.
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Eberhard WL. Correct equations and common approximations for calculating Rayleigh scatter in pure gases and mixtures and evaluation of differences. APPLIED OPTICS 2010; 49:1116-1130. [PMID: 20197809 DOI: 10.1364/ao.49.001116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Equations for Rayleigh scattering in a mixture of gases are derived and compared to frequent approximations in the literature. The traditional Rayleigh scattering equation as modified by King for scatter from a pure gas is correct, whereas another version sometimes appearing in modern literature is erroneous. Use of a mixture's refractive index, which is equivalent to assuming the isotropic molecular polarizabilities of the component gases are identical, is an approximation. Another common approximation is using only number-density weighting of the King factors. Approximation errors can be large when the major components of a mixture have disparate optical properties. Fortunately, the errors for Earth's air are much smaller and comparable to errors from other sources.
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Affiliation(s)
- Wynn L Eberhard
- National Oceanic and Atmospheric Administration Earth System Research Laboratory, 325 Broadway, Boulder, Colorado 80305, USA.
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17
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Ityaksov D, Linnartz H, Ubachs W. Deep-UV absorption and Rayleigh scattering of carbon dioxide. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.07.049] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Fiedler SE, Hese A, Heitmann U. Influence of the cavity parameters on the output intensity in incoherent broadband cavity-enhanced absorption spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2007; 78:073104. [PMID: 17672752 DOI: 10.1063/1.2752608] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The incoherent broadband cavity-enhanced absorption spectroscopy is a technique in measuring small absorptions over a broad wavelength range. The setup consists of a conventional absorption spectrometer using an incoherent lamp and a charge coupled device detector, as well as a linear optical cavity placed around the absorbing sample, which enhances the effective path length through the sample. In this work the consequences of cavity length, mirror curvature, reflectivity, different light injection geometries, and spot size of the light source on the output intensity are studied and the implications to the signal-to-noise ratio of the absorption measurement are discussed. The symmetric confocal resonator configuration is identified as a special case with optimum imaging characteristics but with higher requirements for mechanical stability. Larger spot sizes of the light source were found to be favorable in order to reduce the negative effects of aberrations on the intensity.
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Affiliation(s)
- Sven E Fiedler
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany.
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Ramos C, Dagdigian PJ. Detection of vapors of explosives and explosive-related compounds by ultraviolet cavity ringdown spectroscopy. APPLIED OPTICS 2007; 46:620-7. [PMID: 17230257 DOI: 10.1364/ao.46.000620] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The detection of vapors of dinitrobenzenes and dinitrotoluenes by UV cavity ringdown spectroscopy (CRDS) was investigated. Absorption cross sections at 248 nm were estimated by measurements on saturated vapors and compared with solution-phase values. The computed subparts per 10(9) detection sensitivity with no effort at preconcentration was demonstrated through measurements on diluted flows. The factors affecting measurements on 1 atm total pressure were considered, and it was demonstrated that Rayleigh scattering by air will reduce the detection sensitivity by 5%-10%. The UV absorption spectra of these compounds are broad, resulting in a relatively poor selectivity for single-wavelength measurements with the UV CRDS technique.
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Affiliation(s)
- Christopher Ramos
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218-2685, USA
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20
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Thompson JE, Spangler HD. Tungsten source integrated cavity output spectroscopy for the determination of ambient atmospheric extinction coefficient. APPLIED OPTICS 2006; 45:2465-73. [PMID: 16623244 DOI: 10.1364/ao.45.002465] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Broadband integrated cavity output spectroscopy (ICOS) utilizing an incoherent tungsten lamp as a spectroscopic source is described. This novel approach has been termed W-ICOS. The technique has been applied to make quantitative measurements of Rayleigh scattering by carbon dioxide between 570 and 590 nm and to make measurements of aerosol and atmospheric extinction. Minimum detectable extinction coefficients (kext) made in a 94 cm optical cavity ranged between 3.4 and 35 Mm(-1) depending on the level of signal averaging employed. The level of sensitivity achieved should allow measurements on static gas samples and regular, quantitative measurements of the atmospheric extinction coefficient.
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Sutton JA, Driscoll JF. Rayleigh scattering cross sections of combustion species at 266, 355, and 532 nm for thermometry applications. OPTICS LETTERS 2004; 29:2620-2622. [PMID: 15552664 DOI: 10.1364/ol.29.002620] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Rayleigh scattering cross sections are measured for nine combustion species (Ar, N2, O2, CO2, CO, H2, H2O, CH4, and C3H8) at wavelengths of 266, 355, and 532 nm and at temperatures ranging from 295 to 1525 K. Experimental results show that, as laser wavelengths become shorter, polarization effects become important and the depolarization ratio of the combustion species must be accounted for in the calculation of the Rayleigh scattering cross section. Temperature effects on the scattering cross section are also measured. Only a small temperature dependence is measured for cross sections at 355 nm, resulting in a 2-8% increase in cross section at temperatures of 1500 K. This temperature dependence increases slightly for measurements at 266 nm, resulting in a 5-11% increase in cross sections at temperatures of 1450 K.
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Affiliation(s)
- Jeffrey A Sutton
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109-2140, USA.
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Koch JD, Hanson RK, Koban W, Schulz C. Rayleigh-calibrated fluorescence quantum yield measurements of acetone and 3-pentanone. APPLIED OPTICS 2004; 43:5901-5910. [PMID: 15540449 DOI: 10.1364/ao.43.005901] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We measured fluorescence quantum yields of acetone and 3-pentanone as a pure gas and with nitrogen diluent at room temperature at 20, 507, and 1013 mbar using 248, 266, and 308 nm excitation by calibrating the optical collection system with Rayleigh scattering from nitrogen. At 20 mbar with 308-nm excitation, the fluorescence quantum yields for acetone and 3-pentanone are 7 +/- 1 x 10(-4) and 1.1 +/- 0.2 x 10(-3), respectively, and each decreases with decreasing excitation wavelength. These directly measured values are significantly lower than earlier ones that were based on a chain of relative measurements. The observed pressure and excitation wavelength dependence is in qualitative agreement with a previously developed fluorescence quantum yield model, but the absolute numbers disagree. Changing acetone's fluorescence rate constant to 3 x 10(5) s(-1) from its previous value of 8 x 10(5) s(-1) resulted in good agreement between our measurements and the model.
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Affiliation(s)
- Jon D Koch
- Department of Mechanical Engineering, Stanford University, Building 520, Room 5201, Stanford, California 94302-3032, USA.
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Sneep M, Hannemann S, van Duijn EJ, Ubachs W. Deep-ultraviolet cavity ringdown spectroscopy. OPTICS LETTERS 2004; 29:1378-1380. [PMID: 15233441 DOI: 10.1364/ol.29.001378] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The sensitive optical detection technique of cavity ringdown spectroscopy is extended to the wavelength range 197-204 nm. A novel design narrowband Fourier-transform-limited laser is used, and the technique is applied to gas-phase extinction measurements in CO2, SF6, and O2. Further demonstration of the system capabilities is given in high-resolution recordings of the Schumann-Runge (0, 0), (1,0), and (2, 0) bands in O2.
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Affiliation(s)
- M Sneep
- Laser Centre, Department of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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25
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Robinson AG, Winter PR, Zwier TS. The singlet–triplet spectroscopy of 1,3-butadiene using cavity ring-down spectroscopy. J Chem Phys 2002. [DOI: 10.1063/1.1467903] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Thompson JE, Smith BW, Winefordner JD. Monitoring atmospheric particulate matter through cavity ring-down spectroscopy. Anal Chem 2002; 74:1962-7. [PMID: 12033292 DOI: 10.1021/ac0110505] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cavity ring-down spectroscopy was explored as a means to measure atmospheric optical extinction. Ambient air was sampled through a window on the campus of the University of Florida and transported to a ring-down cell fashioned from standard stainless steel vacuum components. When a copper vapor laser operating at 10 kHz is employed, this arrangement allowed for nearly continuous monitoring of atmospheric extinction at 510 and 578 nm. We have characterized the system performance in terms of detection limit and dynamic range and also monitored a change in atmospheric extinction during a nearby wildfire and fireworks exhibition. The sensitivity and compatibility with automation of the technique renders it useful as a laboratory-based measurement of airborne particulate matter.
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