1
|
Bailey DM, Crump EM, Hodges JT, Fleisher AJ. Direct frequency comb spectroscopy of HCN to evaluate line lists. Faraday Discuss 2023; 245:368-379. [PMID: 37306220 PMCID: PMC10530617 DOI: 10.1039/d3fd00019b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report direct frequency comb spectroscopy of the 2ν1 band of H13CN in the short-wave infrared (λ = 1.56 μm) towards experimental validation of molecular line lists that support observatories like JWST. The laboratory measurements aim to test spectral reference data generated from an experimentally accurate potential energy surface (PES) and an ab initio dipole moment surface (DMS) calculated from quantum chemistry theory. Benchmarking theory with experiment will improve confidence in new astrophysics and astrochemistry inferred from spectroscopic observations of HCN and HNC. Here we describe our instrumentation and initial results using a cross-dispersed spectrometer with a virtually imaged phased array (VIPA).
Collapse
Affiliation(s)
- D Michelle Bailey
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
| | - Eric M Crump
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Joseph T Hodges
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
| | - Adam J Fleisher
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
| |
Collapse
|
2
|
Reed ZD, Tran H, Ngo HN, Hartmann JM, Hodges JT. Effect of Non-Markovian Collisions on Measured Integrated Line Shapes of CO. Phys Rev Lett 2023; 130:143001. [PMID: 37084433 DOI: 10.1103/physrevlett.130.143001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 01/25/2023] [Accepted: 03/10/2023] [Indexed: 05/03/2023]
Abstract
Using cavity ring-down spectroscopy to probe R-branch transitions of CO in N_{2}, we show that the spectral core of the line shapes associated with the first few rotational quantum numbers, J, can be accurately modeled using a sophisticated line profile, provided that a pressure-dependent line area is introduced. This correction vanishes as J increases and is always negligible in CO-He mixtures. The results are supported by molecular dynamics simulations attributing the effect to non-Markovian behavior of collisions at short times. This work has large implications because corrections must be considered for accurate determinations of integrated line intensities, and for spectroscopic databases and radiative transfer codes used for climate predictions and remote sensing.
Collapse
Affiliation(s)
- Zachary D Reed
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Ha Tran
- Laboratoire de Météorologie Dynamique/IPSL, CNRS, Sorbonne Université, Ecole Polytechnique, Institut polytechnique de Paris, Ecole Normale Supérieure, PSL Research University, 4 place Jussieu, 75252, Paris, France
| | - Hoa N Ngo
- Faculty of Physics, Hanoi National University of Education, 136 Xuan Thuy, Cau Giay, Hanoi, Vietnam
| | - Jean-Michel Hartmann
- Laboratoire de Météorologie Dynamique/IPSL, CNRS, Sorbonne Université, Ecole Polytechnique, Institut polytechnique de Paris, Ecole Normale Supérieure, PSL Research University, 4 place Jussieu, 75252, Paris, France
| | - Joseph T Hodges
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| |
Collapse
|
3
|
Srivastava A, Hodges JT. Primary Measurement of Gaseous Elemental Mercury Concentration with a Dynamic Range of Six Decades. Anal Chem 2022; 94:15818-15826. [DOI: 10.1021/acs.analchem.2c03622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Abneesh Srivastava
- Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, Maryland20899, United States
| | - Joseph T. Hodges
- Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology (NIST), 100 Bureau Drive, Gaithersburg, Maryland20899, United States
| |
Collapse
|
4
|
Long DA, Reschovsky BJ, LeBrun TW, Gorman JJ, Hodges JT, Plusquellic DF, Stroud JR. High dynamic range electro-optic dual-comb interrogation of optomechanical sensors. Opt Lett 2022; 47:4323-4326. [PMID: 36048644 DOI: 10.1364/ol.460028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/09/2022] [Indexed: 06/15/2023]
Abstract
An interleaved, chirped electro-optic dual comb system is demonstrated for rapid, high dynamic range measurements of cavity optomechanical sensors. This approach allows for the cavity displacements to be interrogated at measurement times as fast as 10 µs over ranges far larger than can be achieved with alternative methods. While the performance of this novel, to the best of our knowledge, readout approach is evaluated with an optomechanical accelerometer, this method has a wide range of applications including temperature, pressure, and humidity sensing as well as acoustics and molecular spectroscopy.
Collapse
|
5
|
Bielska K, Kyuberis AA, Reed ZD, Li G, Cygan A, Ciuryło R, Adkins EM, Lodi L, Zobov NF, Ebert V, Lisak D, Hodges JT, Tennyson J, Polyansky OL. Subpromille Measurements and Calculations of CO (3-0) Overtone Line Intensities. Phys Rev Lett 2022; 129:043002. [PMID: 35939021 DOI: 10.1103/physrevlett.129.043002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Intensities of lines in the near-infrared second overtone band (3-0) of ^{12}C^{16}O are measured and calculated to an unprecedented degree of precision and accuracy. Agreement between theory and experiment to better than 1‰ is demonstrated by results from two laboratories involving two independent absorption- and dispersion-based cavity-enhanced techniques. Similarly, independent Fourier transform spectroscopy measurements of stronger lines in this band yield mutual agreement and consistency with theory at the 1‰ level. This set of highly accurate intensities can provide an intrinsic reference for reducing biases in future measurements of spectroscopic peak areas.
Collapse
Affiliation(s)
- Katarzyna Bielska
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Torun, Poland
| | - Aleksandra A Kyuberis
- Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Zachary D Reed
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Gang Li
- PTB (Physikalisch-Technische Bundesanstalt), Bundesallee 100, 38116 Braunschweig, Germany
| | - Agata Cygan
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Torun, Poland
| | - Roman Ciuryło
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Torun, Poland
| | - Erin M Adkins
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Lorenzo Lodi
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Nikolay F Zobov
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Volker Ebert
- PTB (Physikalisch-Technische Bundesanstalt), Bundesallee 100, 38116 Braunschweig, Germany
| | - Daniel Lisak
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Torun, Poland
| | - Joseph T Hodges
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Jonathan Tennyson
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Oleg L Polyansky
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom
| |
Collapse
|
6
|
Adkins EM, Hodges JT. Assessment of the precision, bias and numerical correlation of fitted parameters obtained by multi-spectrum fits of the Hartmann-Tran line profile to simulated absorption spectra. J Quant Spectrosc Radiat Transf 2022; 280:10.1016/j.jqsrt.2022.108100. [PMID: 37461431 PMCID: PMC10350967 DOI: 10.1016/j.jqsrt.2022.108100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
Although the Voigt profile has long been used to analyze absorption spectra, the quest for increased precision, accuracy and generality drives the application of advanced models of atomic and molecular line shapes. To this end, the Hartmann-Tran profile is now recommended as a standard for high-resolution spectroscopy because it parameterizes relevant higher-order physical effects, is computationally efficient, and reduces to other widely used profiles as limiting cases. This work explores the uncertainty with which line shape parameters can be obtained from constrained multi-spectrum fits of spectra simulated with this standard profile, varying uncertainty levels in the spectrum detuning and absorption axes, and spanning a range of sampling density, pressure, and line shape parameter values. The analysis focuses on how noise-limited measurement precision of frequency detuning and absorption drive statistical uncertainties in fitted parameters and numerical correlations between these quantities. Also, we quantify the degree of equivalence between the full Hartmann-Tran profile and those derived from it in terms of fitted peak areas and line shape parameters. Finally, we introduce a new open-source software package named Multi-spectrum Analysis Tool for Spectroscopy (MATS), which allows users to fit the HTP and its derived profiles to experimental or simulated absorption spectra to explore the limits of the HTP under actual experimental or user-defined conditions.
Collapse
|
7
|
Lisak D, Charczun D, Nishiyama A, Voumard T, Wildi T, Kowzan G, Brasch V, Herr T, Fleisher AJ, Hodges JT, Ciuryło R, Cygan A, Masłowski P. Dual-comb cavity ring-down spectroscopy. Sci Rep 2022; 12:2377. [PMID: 35149716 PMCID: PMC8837621 DOI: 10.1038/s41598-022-05926-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 01/12/2022] [Indexed: 12/16/2022] Open
Abstract
Cavity ring-down spectroscopy is a ubiquitous optical method used to study light-matter interactions with high resolution, sensitivity and accuracy. However, it has never been performed with the multiplexing advantages of direct frequency comb spectroscopy without significantly compromising spectral resolution. We present dual-comb cavity ring-down spectroscopy (DC-CRDS) based on the parallel heterodyne detection of ring-down signals with a local oscillator comb to yield absorption and dispersion spectra. These spectra are obtained from widths and positions of cavity modes. We present two approaches which leverage the dynamic cavity response to coherently or randomly driven changes in the amplitude or frequency of the probe field. Both techniques yield accurate spectra of methane-an important greenhouse gas and breath biomarker. When combined with broadband frequency combs, the high sensitivity, spectral resolution and accuracy of our DC-CRDS technique shows promise for applications like studies of the structure and dynamics of large molecules, multispecies trace gas detection and isotopic composition.
Collapse
Affiliation(s)
- Daniel Lisak
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100, Toruń, Poland.
| | - Dominik Charczun
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100, Toruń, Poland
| | - Akiko Nishiyama
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100, Toruń, Poland.,National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki, 305-8563, Japan
| | - Thibault Voumard
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - Thibault Wildi
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany
| | - Grzegorz Kowzan
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100, Toruń, Poland
| | - Victor Brasch
- CSEM - Swiss Center for Electronics and Microtechnology, 2000, Neuchâtel, Switzerland
| | - Tobias Herr
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607, Hamburg, Germany.,Physics Department, Universität Hamburg UHH, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - Adam J Fleisher
- Optical Measurements Group, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899, USA
| | - Joseph T Hodges
- Optical Measurements Group, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD, 20899, USA
| | - Roman Ciuryło
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100, Toruń, Poland
| | - Agata Cygan
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100, Toruń, Poland
| | - Piotr Masłowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudziądzka 5, 87-100, Toruń, Poland
| |
Collapse
|
8
|
Hashemi R, Gordon IE, Adkins EM, Hodges JT, Long DA, Birk M, Loos J, Boone CD, Fleisher AJ, Predoi-Cross A, Rothman LS. Improvement of the spectroscopic parameters of the air- and self-broadened N 2O and CO lines for the HITRAN2020 database applications. J Quant Spectrosc Radiat Transf 2021; 271:10.1016/j.jqsrt.2021.107735. [PMID: 37554518 PMCID: PMC10408379 DOI: 10.1016/j.jqsrt.2021.107735] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
This paper outlines the major updates of the line-shape parameters that were performed for the nitrous oxide (N2O) and carbon monoxide (CO) molecules listed in the HITRAN2020 database. We reviewed the collected measurements for the air- and self-broadened N2O and CO spectra to determine proper values for the spectroscopic parameters. Careful comparisons of broadening parameters using the Voigt and speed-dependent Voigt line-shape profiles were performed among various published results for both N2O and CO. Selected data allowed for developing semi-empirical models, which were used to extrapolate/interpolate existing data to update broadening parameters of all the lines of these molecules in the HITRAN database. In addition to the line broadening parameters (and their temperature dependences), the pressure shift values were revised for N2O and CO broadened by air and self for all the bands. The air and self speed-dependence of the broadening parameter for these two molecules were added for every transition as well. Furthermore, we determined the first-order line-mixing parameters using the Exponential Power Gap (EPG) scaling law. These new parameters are now available at HITRAN online.
Collapse
Affiliation(s)
- Robab Hashemi
- Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
| | - Iouli E. Gordon
- Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
| | - Erin M. Adkins
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Joseph T. Hodges
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - David A. Long
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Manfred Birk
- Remote Sensing Technology Institute, German Aerospace Center (DLR), Wessling D-82234, Germany
| | - Joep Loos
- Remote Sensing Technology Institute, German Aerospace Center (DLR), Wessling D-82234, Germany
| | - Chris D. Boone
- Department of Chemistry, University of Waterloo, Ontario, Canada
| | - Adam J. Fleisher
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | | | - Laurence S. Rothman
- Atomic and Molecular Physics Division, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
| |
Collapse
|
9
|
Adkins EM, Long DA, Hodges JT. Air-broadening in near-infrared carbon dioxide line shapes: Quantifying contributions from O2, N2, and Ar. J Quant Spectrosc Radiat Transf 2021; 270:107669. [PMID: 38516121 PMCID: PMC10956487 DOI: 10.1016/j.jqsrt.2021.107669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/23/2024]
Abstract
We measured air broadening in the (30012) ← (00001) carbon dioxide (CO 2 ) band up to J ″ = 50 using frequency-agile rapid scanning cavity ring-down spectroscopy. By using synthetic air samples with varying levels of nitrogen, oxygen, and argon, multi-spectrum fitting allowed for the collisional broadening terms of each major air component to be simultaneously determined in addition to advanced line shape parameters at atmospherically relevant CO 2 mixing ratios. These values were compared to broadener-specific line shape parameters from the literature. Fits to measured spectra were also constrained with results from requantized classical molecular dynamic simulations. We show that this approach enables differentiation between narrowing mechanisms in advanced line shape parameters retrieved from experimental spectra of limited signal-to-noise ratio.
Collapse
Affiliation(s)
- Erin M. Adkins
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - David A. Long
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Joseph T. Hodges
- National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| |
Collapse
|
10
|
Zhao G, Tian J, Hodges JT, Fleisher AJ. Frequency stabilization of a quantum cascade laser by weak resonant feedback from a Fabry-Perot cavity. Opt Lett 2021; 46:3057-3060. [PMID: 34197378 PMCID: PMC9981331 DOI: 10.1364/ol.427083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Frequency-stabilized mid-infrared lasers are valuable tools for precision molecular spectroscopy. However, their implementation remains limited by complicated stabilization schemes. Here we achieve optical self-locking of a quantum cascade laser to the resonant leak-out field of a highly mode-matched two-mirror cavity. The result is a simple approach to achieving stable frequencies from high-powered mid-infrared lasers. For short time scales (<0.1ms), we report a linewidth reduction factor of 3×10-6 to a linewidth of 12 Hz. Furthermore, we demonstrate two-photon cavity-enhanced absorption spectroscopy of an N2O overtone transition near a wavelength of 4.53 µm.
Collapse
Affiliation(s)
- Gang Zhao
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
- Currently with the Institute of Laser Spectroscopy, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan City 030006, Shanxi Province, China
| | - Jianfei Tian
- Institute of Laser Spectroscopy, State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan City 030006, Shanxi Province, China
| | - Joseph T. Hodges
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Adam J. Fleisher
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
- Corresponding author:
| |
Collapse
|
11
|
Adkins EM, Long DA, Fleisher AJ, Hodges JT. Near-infrared cavity ring-down spectroscopy measurements of nitrous oxide in the (4200)←(0000) and (5000)←(0000) bands. J Quant Spectrosc Radiat Transf 2021; 262:10.1016/j.jqsrt.2021.107527. [PMID: 36452911 PMCID: PMC9706648 DOI: 10.1016/j.jqsrt.2021.107527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Using frequency-agile rapid scanning cavity ring-down spectroscopy, we measured line intensities and line shape parameters of 14N2 16O in air in the (4200)←(0000) and (5000)←(0000) bands near 1.6 µm. The absorption spectra were modeled with multi-spectrum fits of Voigt and speed-dependent Voigt profiles. The measured line intensities and air-broadening parameters exhibit deviations of several percent relative to values provided in HITRAN 2016. Our measured intensities for these two bands have relative combined standard uncertainties of ∼1% which is approximately five times smaller than literature values. Comparison of the present air-broadening and speed-dependent broadening parameters to experimental literature values for other rotation-vibration bands of N2O indicates significant differences in magnitude and J-dependence. For applications requiring high spectral fidelity, these results suggest that the assumption of band-independent line shape parameters is not appropriate.
Collapse
|
12
|
Srivastava A, Long SE, Norris JE, Bryan CE, Carney J, Hodges JT. Comparison of Primary Laser Spectroscopy and Mass Spectrometry Methods for Measuring Mass Concentration of Gaseous Elemental Mercury. Anal Chem 2021; 93:1050-1058. [PMID: 33302624 PMCID: PMC8202126 DOI: 10.1021/acs.analchem.0c04002] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a direct comparison between two independent methods for the measurement of gaseous elemental mercury (GEM) mass concentration: isotope dilution cold-vapor inductively coupled plasma mass spectrometry (ID-CV-ICP-MS) and laser absorption spectroscopy (LAS). The former technique combined with passive sorbent tube sampling is currently the primary method at NIST for mercury gas standards traceability to the International System of Units (SI). This traceability is achieved via measurements on a mercury-containing reference material. The latter technique has been recently developed at NIST and involves real-time measurements of light attenuation caused by GEM, with SI traceability based in part on the known spontaneous emission lifetime of the probed 6 1S0-6 3P1 intercombination transition of elemental mercury (Hg0). Using a steady-flow Hg0-in-air generator to produce samples measured by both methods, we use LAS to measure the sample gas and in parallel we collect the Hg0 on sorbent tubes to be subsequently analyzed using ID-CV-ICP-MS. Over the examined mass concentration range (41 μg/m3 to 287 μg/m3 Hg0 in air), the relative disagreement between the two approaches ranged from (1.0 to 1.8)%. The relative combined standard uncertainty on average is 0.4% and 0.9%, for the LAS and MS methods, respectively. Our comparison studies help validate the accuracy of the ID-CV-ICP-MS primary method as well as establish the LAS technique as an attractive alternative primary method for SI-traceable measurements of GEM.
Collapse
Affiliation(s)
- Abneesh Srivastava
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8393, United States
| | - Stephen E. Long
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8393, United States
| | - James E. Norris
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8393, United States
| | - Colleen E. Bryan
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8393, United States
| | - Jennifer Carney
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8393, United States
| | - Joseph T. Hodges
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8393, United States
| |
Collapse
|
13
|
Fleisher AJ, Yi H, Srivastava A, Polyansky OL, Zobov NF, Hodges JT. Absolute 13C/ 12C Isotope Amount Ratio for Vienna Pee Dee Belemnite from Infrared Absorption Spectroscopy. Nat Phys 2021; 17:10.1038/s41567-021-01226-y. [PMID: 36873572 PMCID: PMC9982939 DOI: 10.1038/s41567-021-01226-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Measurements of isotope ratios are predominantly made with reference to standard specimens that have been characterized in the past. In the 1950s, the carbon isotope ratio was referenced to a belemnite sample collected by Heinz Lowenstam and Harold Urey1 in South Carolina's Pee Dee region. Due to the exhaustion of the sample since then, reference materials that are traceable to the original artefact are used to define the Vienna Pee Dee Belemnite (VPDB) scale for stable carbon isotope analysis2. However, these reference materials have also become exhausted or proven to exhibit unstable composition over time3, mirroring issues with the international prototype of the kilogram that led to a revised International System of Units4. A campaign to elucidate the stable carbon isotope ratio of VPDB is underway5, but independent measurement techniques are required to support it. Here we report an accurate value for the stable carbon isotope ratio inferred from infrared absorption spectroscopy, fulfilling the promise of this fundamentally accurate approach6. Our results agree with a value recently derived from mass spectrometry5, and therefore advance the prospects of SI-traceable isotope analysis. Further, our calibration-free method could improve mass balance calculations and enhance isotopic tracer studies in CO2 source apportionment.
Collapse
Affiliation(s)
- Adam J. Fleisher
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- These authors contributed equally: Adam J. Fleisher, Hongming Yi
- To whom correspondence should be addressed: , phone: 301-975-4864, National Institute of Standards and Technology, 100 Bureau Drive, Mailstop 8320, Gaithersburg, MD 20899, USA
| | - Hongming Yi
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
- These authors contributed equally: Adam J. Fleisher, Hongming Yi
- Present affiliation: The Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, USA
| | - Abneesh Srivastava
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Oleg L. Polyansky
- Department of Physics and Astronomy, University College London, London, UK
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Nikolai F. Zobov
- Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russia
| | - Joseph T. Hodges
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
| |
Collapse
|
14
|
Fleurbaey H, Yi H, Adkins EM, Fleisher AJ, Hodges JT. Cavity ring-down spectroscopy of CO 2 near λ = 2.06 μm: Accurate transition intensities for the Orbiting Carbon Observatory-2 (OCO-2) "strong band". J Quant Spectrosc Radiat Transf 2020; 252:https://doi.org/10.1016/j.jqsrt.2020.107104. [PMID: 33100382 DOI: 10.1016/j.jqsrt.2020.107104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The λ = 2.06 μm absorption band of CO2 is widely used for the remote sensing of atmospheric carbon dioxide, making it relevant to many important top-down measurements of carbon flux. The forward models used in the retrieval algorithms employed in these measurements require increasingly accurate line intensity and line shape data from which absorption cross-sections can be computed. To overcome accuracy limitations of existing line lists, we used frequency-stabilized cavity ring-down spectroscopy to measure 39 transitions in the 12C16O2 absorption band. The line intensities were measured with an estimated relative combined standard uncertainty of u r = 0.08 %. We predicted the J-dependence of the measured intensities using two theoretical models: a one-dimensional spectroscopic model with Herman-Wallis rotation-vibration corrections, and a line-by-line ab initio dipole moment surface model [Zak et al. JQSRT 2016;177:31-42]. For the second approach, we fit only a single factor to rescale the theoretical integrated band intensity to be consistent with the measured intensities. We find that the latter approach yields an equally adequate representation of the fitted J-dependent intensity data and provides the most physically general representation of the results. Our recommended value for the integrated band intensity equal to 7.183 × 10-21 cm molecule-1 ± 6 × 10-24 cm molecule-1 is based on the rescaled ab initio model and corresponds to a fitted scale factor of 1.0069 ± 0.0002. Comparisons of literature intensity values to our results reveal systematic deviations ranging from -1.16 % to +0.33 %.
Collapse
Affiliation(s)
- Hélène Fleurbaey
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Hongming Yi
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Erin M Adkins
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Adam J Fleisher
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| | - Joseph T Hodges
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
| |
Collapse
|
15
|
Zhao G, Bailey DM, Fleisher AJ, Hodges JT, Lehmann KK. Doppler-Free Two-Photon Cavity Ring-Down Spectroscopy of a Nitrous Oxide (N 2O) Vibrational Overtone Transition. Phys Rev A (Coll Park) 2020; 101:https://doi.org/10.1103/physreva.101.062509. [PMID: 33103022 PMCID: PMC7580019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report Doppler-free two-photon absorption of N2O at λ = 4.53 μm, measured by cavity ring-down spectroscopy. High power was achieved by optical self-locking of a quantum cascade laser to a linear resonator of finesse F = 22730 , and accurate laser detuning over a 400 MHz range was measured relative to an optical frequency comb. At a sample pressure of p = 0.13 kPa, we report a large two-photon cross-section per molecule of σ 13 ( 2 ) = 8.0 × 10 - 41 cm4 s for the Q(18) rovibrational transition at a resonant frequency of ν 0 = 66179400.8 MHz.
Collapse
Affiliation(s)
- Gang Zhao
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899
| | - D. Michelle Bailey
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899
| | - Adam J. Fleisher
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899
| | - Joseph T. Hodges
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899
| | - Kevin K. Lehmann
- Departments of Chemistry and Physics, University of Virginia, Charlottesville, Virginia 22904
| |
Collapse
|
16
|
Fleisher AJ, Adkins EM, Reed ZD, Yi H, Long DA, Fleurbaey HM, Hodges JT. Twenty-Five-Fold Reduction in Measurement Uncertainty for a Molecular Line Intensity. Phys Rev Lett 2019; 123:043001. [PMID: 31491247 PMCID: PMC6767615 DOI: 10.1103/physrevlett.123.043001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/06/2019] [Indexed: 05/06/2023]
Abstract
To accurately attribute sources and sinks of molecules like CO_{2}, remote sensing missions require line intensities (S) with relative uncertainties u_{r}(S)<0.1%. However, discrepancies in S of ≈1% are common when comparing different experiments, thus limiting their potential impact. Here we report a cavity ring-down spectroscopy multi-instrument comparison which revealed that the hardware used to digitize analog ring-down signals caused variability in spectral integrals which yield S. Our refined approach improved measurement accuracy 25-fold, resulting in u_{r}(S)=0.06%.
Collapse
Affiliation(s)
- Adam J Fleisher
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
| | - Erin M Adkins
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
| | - Zachary D Reed
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
| | - Hongming Yi
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
| | - David A Long
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
| | - Hélène M Fleurbaey
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
| | - Joseph T Hodges
- National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
| |
Collapse
|
17
|
Srivastava A, Hodges JT. Correction to Development of a High-Resolution Laser Absorption Spectroscopy Method with Application to the Determination of Absolute Concentration of Gaseous Elemental Mercury in Air. Anal Chem 2019; 91:4920. [DOI: 10.1021/acs.analchem.9b01348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
Mendonca J, Strong K, Wunch D, Toon GC, Long DA, Hodges JT, Sironneau VT, Franklin JE. Using a Speed-Dependent Voigt Line Shape to Retrieve O 2 from Total Carbon Column Observing Network Solar Spectra to Improve Measurements of XCO 2. Atmos Meas Tech 2019; 12:10.5194/amt-12-35-2019. [PMID: 31579431 PMCID: PMC6774361 DOI: 10.5194/amt-12-35-2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
High-resolution, laboratory, absorption spectra of the a 1 Δ g ← X 3 ∑ g - oxygen (O2) band measured using cavity ring-down spectroscopy were fitted using the Voigt and speed-dependent Voigt line shapes. We found that the speed-dependent Voigt line shape was better able to model the measured absorption coefficients than the Voigt line shape. We used these line shape models to calculate absorption coefficients to retrieve atmospheric total columns abundances of O2 from ground-based spectra from four Fourier transform spectrometers that are apart of the Total Carbon Column Observing Network (TCCON) Lower O2 total columns were retrieved with the speed-dependent Voigt line shape, and the difference between the total columns retrieved using the Voigt and speed-dependent Voigt line shapes increased as a function of solar zenith angle. Previous work has shown that carbon dioxide (CO2) total columns are better retrieved using a speed-dependent Voigt line shape with line mixing. The column-averaged dry-air mole fraction of CO2 (XCO2) was calculated using the ratio between the columns of CO2 and O2 retrieved (from the same spectra) with both line shapes from measurements made over a one-year period at the four sites. The inclusion of speed dependence in the O2 retrievals significantly reduces the airmass dependence of XCO2 and the bias between the TCCON measurements and calibrated integrated aircraft profile measurements was reduced from 1% to 0.4%. These results suggest that speed dependence should be included in the forward model when fitting near-infrared CO2 and O2 spectra to improve the accuracy of XCO2 measurements.
Collapse
Affiliation(s)
- Joseph Mendonca
- Department of Physics, University of Toronto, Toronto, ON, Canada
| | - Kimberly Strong
- Department of Physics, University of Toronto, Toronto, ON, Canada
| | - Debra Wunch
- Department of Physics, University of Toronto, Toronto, ON, Canada
| | | | - David A. Long
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Joseph T. Hodges
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | | - Jonathan E. Franklin
- Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, USA
| |
Collapse
|
19
|
Srivastava A, Hodges JT. Development of a High-Resolution Laser Absorption Spectroscopy Method with Application to the Determination of Absolute Concentration of Gaseous Elemental Mercury in Air. Anal Chem 2018; 90:6781-6788. [PMID: 29708730 PMCID: PMC6032520 DOI: 10.1021/acs.analchem.8b00757] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Isotope dilution-cold-vapor-inductively coupled plasma mass spectrometry (ID-CV-ICPMS) has become the primary standard for measurement of gaseous elemental mercury (GEM) mass concentration. However, quantitative mass spectrometry is challenging for several reasons including (1) the need for isotopic spiking with a standard reference material, (2) the requirement for bias-free passive sampling protocols, (3) the need for stable mass spectrometry interface design, and (4) the time and cost involved for gas sampling, sample processing, and instrument calibration. Here, we introduce a high-resolution laser absorption spectroscopy method that eliminates the need for sample-specific calibration standards or detailed analysis of sample treatment losses. This technique involves a tunable, single-frequency laser absorption spectrometer that measures isotopically resolved spectra of elemental mercury (Hg) spectra of 6 1S0 ← 6 3P1 intercombination transition near λ = 253.7 nm. Measured spectra are accurately modeled from first-principles using the Beer-Lambert law and Voigt line profiles combined with literature values for line positions, line shape parameters, and the spontaneous emission Einstein coefficient to obtain GEM mass concentration values. We present application of this method for the measurement of the equilibrium concentration of mercury vapor near room temperature. Three closed systems are considered: two-phase mixtures of liquid Hg and its vapor and binary two-phase mixtures of Hg-air and Hg-N2 near atmospheric pressure. Within the experimental relative standard uncertainty, 0.9-1.5% congruent values of the equilibrium Hg vapor concentration are obtained for the Hg-only, Hg-air, Hg-N2 systems, in confirmation with thermodynamic predictions. We also discuss detection limits and the potential of the present technique to serve as an absolute primary standard for measurements of gas-phase mercury concentration and isotopic composition.
Collapse
Affiliation(s)
- Abneesh Srivastava
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8393, United States
| | - Joseph T. Hodges
- Chemical Sciences Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8393, United States
| |
Collapse
|
20
|
Rhoderick GC, Kelley ME, Miller WR, Norris JE, Carney J, Gameson L, Cecelski CE, Harris KJ, Goodman CA, Srivastava A, Hodges JT. NIST Standards for Measurement, Instrument Calibration, and Quantification of Gaseous Atmospheric Compounds. Anal Chem 2018; 90:4711-4718. [PMID: 29498261 DOI: 10.1021/acs.analchem.7b05310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There are many gas phase compounds present in the atmosphere that affect and influence the earth's climate. These compounds absorb and emit radiation, a process which is the fundamental cause of the greenhouse effect. The major greenhouse gases in the earth's atmosphere are carbon dioxide, methane, nitrous oxide, and ozone. Some halocarbons are also strong greenhouse gases and are linked to stratospheric ozone depletion. Hydrocarbons and monoterpenes are precursors and contributors to atmospheric photochemical processes, which lead to the formation of particulates and secondary photo-oxidants such as ozone, leading to photochemical smog. Reactive gases such as nitric oxide and sulfur dioxide are also compounds found in the atmosphere and generally lead to the formation of other oxides. These compounds can be oxidized in the air to acidic and corrosive gases and contribute to photochemical smog. Measurements of these compounds in the atmosphere have been ongoing for decades to track growth rates and assist in curbing emissions of these compounds into the atmosphere. To accurately establish mole fraction trends and assess the role of these gas phase compounds in atmospheric chemistry, it is essential to have good calibration standards. The National Institute of Standards and Technology has been developing standards of many of these compounds for over 40 years. This paper discusses the development of these standards.
Collapse
Affiliation(s)
- George C Rhoderick
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Michael E Kelley
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Walter R Miller
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - James E Norris
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Jennifer Carney
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Lyn Gameson
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Christina E Cecelski
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Kimberly J Harris
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Cassie A Goodman
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Abneesh Srivastava
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| | - Joseph T Hodges
- Gas Sensing Metrology Group, Chemical Sciences Division, Materials Measurement Laboratory , National Institute of Standards and Technology , 100 Bureau Drive , Gaithersburg , Maryland 20899-8393 , United States
| |
Collapse
|
21
|
Yi H, Liu Q, Gameson L, Fleisher AJ, Hodges JT. High-accuracy 12C 16O 2 line intensities in the 2 μm wavelength region measured by frequency-stabilized cavity ring-down spectroscopy. J Quant Spectrosc Radiat Transf 2018; 206:367-377. [PMID: 29731521 PMCID: PMC5930389 DOI: 10.1016/j.jqsrt.2017.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Reported here are highly accurate, experimentally measured ro-vibrational transition intensities for the R-branch of the (20012) - (00001) 12C16O2 band near λ = 2 μm. Measurements were performed by a frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) instrument designed to achieve precision molecular spectroscopy in this important region of the infrared. Through careful control and traceable characterization of CO2 sample conditions, and through high-fidelity measurements spanning several months in time, we achieve relative standard uncertainties for the reported transition intensities between 0.15 % and 0.46 %. Such high accuracy spectroscopy is shown to provide a stringent test of calculated potential energy and ab initio dipole moment surfaces, and therefore transition intensities calculated from first principles.
Collapse
|
22
|
Fleisher AJ, Long DA, Hodges JT. Quantitative modeling of complex molecular response in coherent cavity-enhanced dual-comb spectroscopy. J Mol Spectrosc 2018; 352:10.1016/j.jms.2018.07.010. [PMID: 30983629 PMCID: PMC6459610 DOI: 10.1016/j.jms.2018.07.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present a complex-valued electric field model for experimentally observed cavity transmission in coherent cavity-enhanced (CE) multiplexed spectroscopy (i.e., dual-comb spectroscopy, DCS). The transmission model for CE-DCS differs from that previously derived for Fourier-transform CE direct frequency comb spectroscopy [Foltynowicz et al., Appl. Phys. B 110, 163-175 (2013)] by the treatment of the local oscillator which, in the case of CE-DCS, does not interact with the enhancement cavity. Validation is performed by measurements of complex-valued near-infrared spectra of CO and CO2 by an electro-optic frequency comb coherently coupled to an enhancement cavity of finesse F = 19600. Following validation, we measure the 30012 ← 00001 12C16O2 vibrational band origin with a combined standard uncertainty of 770 kHz (fractional uncertainty of 4 × 10-9).
Collapse
Affiliation(s)
- Adam J. Fleisher
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, U.S.A
| | - David A. Long
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, U.S.A
| | - Joseph T. Hodges
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, U.S.A
| |
Collapse
|
23
|
Fleisher AJ, Long DA, Liu Q, Gameson L, Hodges JT. Optical Measurement of Radiocarbon below Unity Fraction Modern by Linear Absorption Spectroscopy. J Phys Chem Lett 2017; 8:4550-4556. [PMID: 28880564 PMCID: PMC5725230 DOI: 10.1021/acs.jpclett.7b02105] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
High-precision measurements of radiocarbon (14C) near or below a fraction modern 14C of 1 (F14C ≤ 1) are challenging and costly. An accurate, ultrasensitive linear absorption approach to detecting 14C would provide a simple and robust benchtop alternative to off-site accelerator mass spectrometry facilities. Here we report the quantitative measurement of 14C in gas-phase samples of CO2 with F14C < 1 using cavity ring-down spectroscopy in the linear absorption regime. Repeated analysis of CO2 derived from the combustion of either biogenic or petrogenic sources revealed a robust ability to differentiate samples with F14C < 1. With a combined uncertainty of 14C/12C = 130 fmol/mol (F14C = 0.11), initial performance of the calibration-free instrument is sufficient to investigate a variety of applications in radiocarbon measurement science including the study of biofuels and bioplastics, illicitly traded specimens, bomb dating, and atmospheric transport.
Collapse
|
24
|
Drouin BJ, Benner DC, Brown LR, Cich MJ, Crawford TJ, Devi VM, Guillaume A, Hodges JT, Mlawer EJ, Robichaud DJ, Oyafuso F, Payne VH, Sung K, Wishnow EH, Yu S. Multispectrum analysis of the oxygen A-band. J Quant Spectrosc Radiat Transf 2017; 186:118-138. [PMID: 27840454 PMCID: PMC5103325 DOI: 10.1016/j.jqsrt.2016.03.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure O2 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line-shape model (Rautian or Speed-Dependent Voigt) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, however, this work presents an integrated self-consistent model developed to ensure the best accuracy. It is also important to consider multiple sources of spectroscopic data for such a study in order to improve the dynamic range of the model and to minimize effects of instrumentation and associated systematic errors. The techniques of Fourier Transform Spectroscopy (FTS) and Cavity Ring-Down Spectroscopy (CRDS) allow complimentary information for such an analysis. We utilize multispectrum fitting software to generate a comprehensive new database with improved accuracy based on these datasets. The extensive information will be made available as a multi-dimensional cross-section (ABSCO) table and the parameterization will be offered for inclusion in the HITRANonline database.
Collapse
Affiliation(s)
- Brian J Drouin
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| | - D Chris Benner
- Department of Physics, College of William and Mary, Williamsburg, VA, USA
| | - Linda R Brown
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| | - Matthew J Cich
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| | - Timothy J Crawford
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| | - V Malathy Devi
- Department of Physics, College of William and Mary, Williamsburg, VA, USA
| | - Alexander Guillaume
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| | - Joseph T Hodges
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA
| | - Eli J Mlawer
- Atmospheric and Environmental Research, Lexington, MA, USA
| | - David J Robichaud
- National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, USA
| | - Fabiano Oyafuso
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| | - Vivienne H Payne
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| | - Keeyoon Sung
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| | - Edward H Wishnow
- University of California Berkeley, Department of Physics and Space Sciences Laboratory, Berkeley, CA 94720, USA
| | - Shanshan Yu
- Jet Propulsion Laboratory - NASA, California Institute of Technology, 4800, Oak Grove Drive, Pasadena, CA 91109-8099, USA
| |
Collapse
|
25
|
Abstract
Dual-comb spectroscopy allows for the rapid, multiplexed acquisition of high-resolution spectra without the need for moving parts or low-resolution dispersive optics. This method of broadband spectroscopy is most often accomplished via tight phase locking of two mode-locked lasers or via sophisticated signal processing algorithms, and therefore, long integration times of phase coherent signals are difficult to achieve. Here we demonstrate an alternative approach to dual-comb spectroscopy using two phase modulator combs originating from a single continuous-wave laser capable of > 2 hours of coherent real-time averaging. The dual combs were generated by driving the phase modulators with step-recovery diodes where each comb consisted of > 250 teeth with 203 MHz spacing and spanned > 50 GHz region in the near-infrared. The step-recovery diodes are passive devices that provide low-phase-noise harmonics for efficient coupling into an enhancement cavity at picowatt optical powers. With this approach, we demonstrate the sensitivity to simultaneously monitor ambient levels of CO2, CO, HDO, and H2O in a single spectral region at a maximum acquisition rate of 150 kHz. Robust, compact, low-cost and widely tunable dual-comb systems could enable a network of distributed multiplexed optical sensors.
Collapse
Affiliation(s)
- Adam J. Fleisher
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland, 20899, USA
| | - David A. Long
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland, 20899, USA
| | - Zachary D. Reed
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland, 20899, USA
| | - Joseph T. Hodges
- Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland, 20899, USA
| | - David F. Plusquellic
- Physical Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado, 80305, USA
| |
Collapse
|
26
|
Fleisher AJ, Long DA, Liu Q, Hodges JT. Precision Interferometric Measurements of Mirror Birefringence in High-Finesse Optical Resonators. Phys Rev A (Coll Park) 2016; 93:013833. [PMID: 27088133 PMCID: PMC4832426 DOI: 10.1103/physreva.93.013833] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
High-finesse optical resonators found in ultrasensitive laser spectrometers utilize supermirrors ideally consisting of isotropic high-reflectivity coatings. Strictly speaking, however, the optical coatings are often non-uniformly stressed during the deposition process and therefore do possess some small amount of birefringence. When physically mounted the cavity mirrors can be additionally stressed in such a way that large optical birefringence is induced. Here we report a direct measurement of optical birefringence in a two-mirror Fabry-Pérot cavity with R = 99.99 % by observing TEM00 mode beating during cavity decays. Experiments were performed at a wavelength of 4.53 μm, with precision limited by both quantum and technical noise sources. We report a splitting of δν = 618(1) Hz, significantly less than the intrinsic cavity linewidth of δcav ≈ 3 kHz. With a cavity free spectral range of 96.9 MHz, the equivalent fractional change in mirror refractive index due to birefringence is therefore Δn/n = 6.38(1) × 10-6.
Collapse
|
27
|
Polyansky OL, Bielska K, Ghysels M, Lodi L, Zobov NF, Hodges JT, Tennyson J. High-Accuracy CO(2) Line Intensities Determined from Theory and Experiment. Phys Rev Lett 2015; 114:243001. [PMID: 26196972 DOI: 10.1103/physrevlett.114.243001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Indexed: 05/22/2023]
Abstract
Atmospheric CO(2) concentrations are being closely monitored by remote sensing experiments which rely on knowing line intensities with an uncertainty of 0.5% or better. Most available laboratory measurements have uncertainties much larger than this. We report a joint experimental and theoretical study providing rotation-vibration line intensities with the required accuracy. The ab initio calculations are extendible to all atmospherically important bands of CO(2) and to its isotologues. As such, they will form the basis for detailed CO(2) spectroscopic line lists for future studies.
Collapse
Affiliation(s)
- Oleg L Polyansky
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
- Institute of Applied Physics, Russian Academy of Sciences, Ulyanov Street 46, Nizhny Novgorod 603950, Russia
| | - Katarzyna Bielska
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland
| | - Mélanie Ghysels
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Lorenzo Lodi
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - Nikolai F Zobov
- Institute of Applied Physics, Russian Academy of Sciences, Ulyanov Street 46, Nizhny Novgorod 603950, Russia
| | - Joseph T Hodges
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Jonathan Tennyson
- Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| |
Collapse
|
28
|
Cygan A, Wcisło P, Wójtewicz S, Masłowski P, Hodges JT, Ciuryło R, Lisak D. One-dimensional frequency-based spectroscopy. Opt Express 2015; 23:14472-14486. [PMID: 26072808 DOI: 10.1364/oe.23.014472] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recent developments in optical metrology have tremendously improved the precision and accuracy of the horizontal (frequency) axis in measured spectra. However, the vertical (typically absorbance) axis is usually based on intensity measurements that are subject to instrumental errors which limit the spectrum accuracy. Here we report a one-dimensional spectroscopy that uses only the measured frequencies of high-finesse cavity modes to provide complete information about the dispersive properties of the spectrum. Because this technique depends solely on the measurement of frequencies or their differences, it is insensitive to systematic errors in the detection of light intensity and has the potential to become the most accurate of all absorptive and dispersive spectroscopic methods. The experimental results are compared to measurements by two other high-precision cavity-enhanced spectroscopy methods. We expect that the proposed technique will have significant impact in fields such as fundamental physics, gas metrology and environmental remote sensing.
Collapse
|
29
|
Tennyson J, Bernath PF, Campargue A, Császár AG, Daumont L, Gamache RR, Hodges JT, Lisak D, Naumenko OV, Rothman LS, Tran H, Zobov NF, Buldyreva J, Boone CD, De Vizia MD, Gianfrani L, Hartmann JM, McPheat R, Weidmann D, Murray J, Ngo NH, Polyansky OL. Recommended isolated-line profile for representing high-resolution spectroscopic transitions (IUPAC Technical Report). PURE APPL CHEM 2014. [DOI: 10.1515/pac-2014-0208] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The report of an IUPAC Task Group, formed in 2011 on “Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory” (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. The well-documented inadequacies of the Voigt profile (VP), used almost universally by databases and radiative-transfer codes, to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule have resulted in the development of a variety of alternative line-profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially Correlated quadratic-Speed-Dependent Hard-Collision profile (pCqSD-HCP) should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should be called the Hartmann–Tran profile (HTP). The HTP is sophisticated enough to capture the various collisional contributions to the isolated line shape, can be computed in a straightforward and rapid manner, and reduces to simpler profiles, including the Voigt profile, under certain simplifying assumptions.
Collapse
|
30
|
Long DA, Fleisher AJ, Douglass KO, Maxwell SE, Bielska K, Hodges JT, Plusquellic DF. Multiheterodyne spectroscopy with optical frequency combs generated from a continuous-wave laser. Opt Lett 2014; 39:2688-90. [PMID: 24784078 DOI: 10.1364/ol.39.002688] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Dual-drive Mach-Zehnder modulators were utilized to produce power-leveled optical frequency combs (OFCs) from a continuous-wave laser. The resulting OFCs contained up to 50 unique frequency components and spanned more than 200 GHz. Simple changes to the modulation frequency allowed for agile control of the comb spacing. These OFCs were then utilized for broadband, multiheterodyne measurements of CO2 using both a multipass cell and an optical cavity. This technique allows for robust measurements of trace gas species and alleviates much of the cost and complexity associated with the use of femtosecond OFCs produced with mode-locked pulsed lasers.
Collapse
|
31
|
Radney JG, You R, Ma X, Conny JM, Zachariah MR, Hodges JT, Zangmeister CD. Dependence of soot optical properties on particle morphology: measurements and model comparisons. Environ Sci Technol 2014; 48:3169-3176. [PMID: 24548253 DOI: 10.1021/es4041804] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report the first mass-specific absorption and extinction cross sections for size- and mass-selected laboratory-generated soot aerosol. Measurement biases associated with aerosols possessing multiple charges were eliminated using mass selection to isolate singly charged particles for a specified electrical mobility diameter. Aerosol absorption and extinction coefficients were measured using photoacoustic and cavity ring-down spectroscopy techniques, respectively, for lacey and compacted soot morphologies. The measurements show that the mass-specific absorption cross sections are proportional to particle mass and independent of morphology, with values between 5.7 and 6 m(2) g(-1). Mass-specific extinction cross sections were morphology dependent and ranged between 12 and 16 m(2) g(-1) for the lacey and compact morphologies, respectively. The resulting single-scattering albedos ranged from 0.5 to 0.6. Results are also compared to theoretical calculations of light absorption and scattering from simulated particle agglomerates. The observed absorption is relatively well modeled, with minimum differences between the calculated and measured mass absorption cross sections ranging from ∼ 5% (lacey soot) to 14% (compact soot). The model, however, was unable to satisfactorily reproduce the measured extinction, underestimating the single-scattering albedo for both particle morphologies. These discrepancies between calculations and measurements underscore the need for validation and refinement of existing models of light scattering and absorption by soot agglomerates.
Collapse
Affiliation(s)
- James G Radney
- Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | | | | | | | | | | | | |
Collapse
|
32
|
Tennyson J, Bernath PF, Brown LR, Campargue A, Császár AG, Daumont L, Gamache RR, Hodges JT, Naumenko OV, Polyansky OL, Rothman LS, Vandaele AC, Zobov NF. A database of water transitions from experiment and theory (IUPAC Technical Report). PURE APPL CHEM 2014. [DOI: 10.1515/pac-2014-5012] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Abstract
The report and results of an IUPAC Task Group (TG) formed in 2004 on “A Database of Water Transitions from Experiment and Theory” (Project No. 2004-035-1-100) are presented. Energy levels and recommended labels involving exact and approximate quantum numbers for the main isotopologues of water in the gas phase, H216O, H218O, H217O, HD16O, HD18O, HD17O, D216O, D218O, and D217O, are determined from measured transition frequencies. The transition frequencies and energy levels are validated using first-principles nuclear motion computations and the MARVEL (measured active rotational–vibrational energy levels) approach. The extensive data including lines and levels are required for analysis and synthesis of spectra, thermochemical applications, the construction of theoretical models, and the removal of spectral contamination by ubiquitous water lines. These datasets can also be used to assess where measurements are lacking for each isotopologue and to provide accurate frequencies for many yet-to-be measured transitions. The lack of high-quality frequency calibration standards in the near infrared is identified as an issue that has hindered the determination of high-accuracy energy levels at higher frequencies. The generation of spectra using the MARVEL energy levels combined with transition intensities computed using high accuracy ab initio dipole moment surfaces are discussed. A recommendation of the TG is for further work to identify a single, suitable model to represent pressure- (and temperature-) dependent line profiles more accurately than Voigt profiles.
Collapse
|
33
|
Radney JG, Ma X, Gillis KA, Zachariah MR, Hodges JT, Zangmeister CD. Direct measurements of mass-specific optical cross sections of single-component aerosol mixtures. Anal Chem 2013; 85:8319-25. [PMID: 23875772 DOI: 10.1021/ac401645y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The optical properties of atmospheric aerosols vary widely, being dependent upon particle composition, morphology, and mixing state. This diversity and complexity of aerosols motivates measurement techniques that can discriminate and quantify a variety of single- and multicomponent aerosols that are both internally and externally mixed. Here, we present a new combination of techniques to directly measure the mass-specific extinction and absorption cross sections of laboratory-generated aerosols that are relevant to atmospheric studies. Our approach employs a tandem differential mobility analyzer, an aerosol particle mass analyzer, cavity ring-down and photoacoustic spectrometers, and a condensation particle counter. This suite of instruments enables measurement of aerosol particle size, mass, extinction and absorption coefficients, and aerosol number density, respectively. Taken together, these observables yield the mass-specific extinction and absorption cross sections without the need to model particle morphology or account for sample collection artifacts. Here we demonstrate the technique in a set of case studies which involve complete separation of aerosol by charge, separation of an external mixture by mass, and discrimination between particle types by effective density and single-scattering albedo.
Collapse
Affiliation(s)
- James G Radney
- Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | | | | | | | | | | |
Collapse
|
34
|
Abstract
We present a technique called coupled-cavity ring-down spectroscopy (CC-RDS) for controlling the finesse of an optical resonator. Applications include extending the sensitivity and dynamic range of a cavity-enhanced spectrometer as well as widening the useful spectral region of high-reflectivity mirrors. CC-RDS uses controlled feedback of the probe laser beam to a ring-down cavity, which leads to interference between the internally circulating light and that which is fed back through a cavity mirror port. Using a 74 cm long ring-down cavity and a feedback cavity with a finesse of 16, we demonstrate that this effect increases the decay time constant from 210 μs to 280 μs, corresponding to an increase of finesse from 2.7×10(5) to 3.6×10(5). Finally, we show that with the addition of a second feedback cavity, we observe ring-down times as long as ~0.5 ms, which is equivalent to (1-R)≈4.9×10(-6), where R is the effective mirror reflectivity.
Collapse
Affiliation(s)
- Jérémie Courtois
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | | |
Collapse
|
35
|
|
36
|
Bielska K, Havey DK, Scace GE, Lisak D, Hodges JT. Spectroscopic measurement of the vapour pressure of ice. Philos Trans A Math Phys Eng Sci 2012; 370:2509-2519. [PMID: 22547230 DOI: 10.1098/rsta.2011.0188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a laser absorption technique to measure the saturation vapour pressure of hexagonal ice. This method is referenced to the triple-point state of water and uses frequency-stabilized cavity ring-down spectroscopy to probe four rotation-vibration transitions of at wavenumbers near 7180 cm(-1). Laser measurements are made at the output of a temperature-regulated standard humidity generator, which contains ice. The dynamic range of the technique is extended by measuring the relative intensities of three weak/strong transition pairs at fixed ice temperature and humidity concentration. Our results agree with a widely used thermodynamically derived ice vapour pressure correlation over the temperature range 0°C to -70°C to within 0.35 per cent.
Collapse
Affiliation(s)
- K Bielska
- Instytut Fizyki, Uniwersytet Mikołaja Kopernika, ul. Grudziadzka 5/7, 87-100 Toruń, Poland
| | | | | | | | | |
Collapse
|
37
|
Long DA, Bielska K, Lisak D, Havey DK, Okumura M, Miller CE, Hodges JT. The air-broadened, near-infrared CO2 line shape in the spectrally isolated regime: Evidence of simultaneous Dicke narrowing and speed dependence. J Chem Phys 2011; 135:064308. [PMID: 21842934 DOI: 10.1063/1.3624527] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- David A Long
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | | | | | | | | | | | | |
Collapse
|
38
|
Cygan A, Lisak D, Masłowski P, Bielska K, Wójtewicz S, Domysławska J, Trawiński RS, Ciuryło R, Abe H, Hodges JT. Pound-Drever-Hall-locked, frequency-stabilized cavity ring-down spectrometer. Review of Scientific Instruments 2011; 82:063107. [PMID: 21721674 DOI: 10.1063/1.3595680] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We describe a high sensitivity and high spectral resolution laser absorption spectrometer based upon the frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) technique. We used the Pound-Drever-Hall (PDH) method to lock the probe laser to the high-finesse ring-down cavity. We show that the concomitant narrowing of the probe laser line width leads to dramatically increased ring-down event acquisition rates (up to 14.3 kHz), improved spectrum signal-to-noise ratios for weak O(2) absorption spectra at λ = 687 nm and substantial increase in spectrum acquisition rates compared to implementations of FS-CRDS that do not incorporate high-bandwidth locking techniques. The minimum detectable absorption coefficient and the noise-equivalent absorption coefficient for the spectrometer are about 2×10(-10) cm(-1) and 7.5×10(-11) cm(-1)Hz(-1/2), respectively.
Collapse
Affiliation(s)
- A Cygan
- Instytut Fizyki, Uniwersytet Mikołaja Kopernika, ul. Grudziadzka 5/7, 87-100 Toruń, Poland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Havey DK, Bueno PA, Gillis KA, Hodges JT, Mulholland GW, van Zee RD, Zachariah MR. Photoacoustic Spectrometer with a Calculable Cell Constant for Measurements of Gases and Aerosols. Anal Chem 2010; 82:7935-42. [DOI: 10.1021/ac101366e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel K. Havey
- Department of Chemistry and Biochemistry, James Madison University, MSC 4501, Harrisonburg, Virginia 22807, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, and Department of Mechanical Engineering and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - Pedro A. Bueno
- Department of Chemistry and Biochemistry, James Madison University, MSC 4501, Harrisonburg, Virginia 22807, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, and Department of Mechanical Engineering and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - Keith A. Gillis
- Department of Chemistry and Biochemistry, James Madison University, MSC 4501, Harrisonburg, Virginia 22807, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, and Department of Mechanical Engineering and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - Joseph T. Hodges
- Department of Chemistry and Biochemistry, James Madison University, MSC 4501, Harrisonburg, Virginia 22807, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, and Department of Mechanical Engineering and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - George W. Mulholland
- Department of Chemistry and Biochemistry, James Madison University, MSC 4501, Harrisonburg, Virginia 22807, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, and Department of Mechanical Engineering and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - Roger D. van Zee
- Department of Chemistry and Biochemistry, James Madison University, MSC 4501, Harrisonburg, Virginia 22807, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, and Department of Mechanical Engineering and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| | - Michael R. Zachariah
- Department of Chemistry and Biochemistry, James Madison University, MSC 4501, Harrisonburg, Virginia 22807, Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, and Department of Mechanical Engineering and Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742
| |
Collapse
|
40
|
Gillis KA, Havey DK, Hodges JT. Standard photoacoustic spectrometer: model and validation using O2 A-band spectra. Rev Sci Instrum 2010; 81:064902. [PMID: 20590262 DOI: 10.1063/1.3436660] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We model and measure the absolute response of an intensity-modulated photoacoustic spectrometer comprising a 10 cm long resonator and having a Q-factor of approximately 30. We present a detailed theoretical analysis of the system and predict its response as a function of gas properties, resonance frequency, and sample energy transfer relaxation rates. We use a low-power continuous wave laser to probe O(2) A-band absorption transitions using atmospheric, humidified air as the sample gas to calibrate the system. This approach provides a convenient and well-characterized method for calibrating the absolute response of the system provided that water-vapor-mediated relaxation effects are properly taken into account. We show that for photoacoustic spectroscopy (PAS) of the O(2) A-band, the maximum conversion efficiency of absorbed photon energy to acoustic energy is approximately 40% and is limited by finite collision-induced relaxation rates between the two lowest-lying excited electronic states of O(2). PAS also shows great potential for high-resolution line shape measurements: calculated and experimental values for the PAS system response differ by about 1%.
Collapse
Affiliation(s)
- K A Gillis
- Process Measurements Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
| | | | | |
Collapse
|
41
|
Robichaud DJ, Yeung LY, Long DA, Okumura M, Havey DK, Hodges JT, Miller CE, Brown LR. Experimental Line Parameters of the b1Σg+← X3Σg−Band of Oxygen Isotopologues at 760 nm Using Frequency-Stabilized Cavity Ring-Down Spectroscopy. J Phys Chem A 2009; 113:13089-99. [DOI: 10.1021/jp901127h] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
42
|
Abstract
Several rotational lines in the S and Q branches [including the previously unobserved Q(2) and Q(3) lines] of the 3-0 electric quadrupole band of H2 have been detected by cavity ring-down spectroscopy. Line strengths were measured at densities between 2.7x10(18) and 7.5x10(19) molecules cm-3 at room temperature. The observed line strengths in the S branch are consistent with earlier measurements, and systematically below theoretical calculations [relative differences of approximately 10% for the S(1),S(2), and S(3) lines, and nearly 30% for the S(0) line]. Line strength measurements for the Q branch range from 25% to 33% below theoretical calculations.
Collapse
Affiliation(s)
- Daniel C Robie
- Department of Chemistry, York College, City University of New York, Jamaica, New York 11451, USA.
| | | |
Collapse
|
43
|
Abstract
We have used a continuous-wave carbon dioxide laser in a single-mode realization of cavity ring-down spectroscopy to measure absorption coefficients of water vapor at 944 cm(-1) for several temperatures in the range 270-315 K. The conventional description of water vapor infrared absorption is applied, in which the absorption is modeled in two parts consisting of local line absorption and the remaining residual absorption, which has become known as the water vapor continuum. This water vapor continuum consists of distinct water-water, water-nitrogen, and water-oxygen continua. The water-water continuum absorption coefficient is found to have a magnitude of C(s)(296 K) = (1.82+/-0.02) x 10(-22) cm(2) molecule(-1) atm(-1), and the water-nitrogen coefficient has a magnitude of C(n)(296 K) = (7.3 +/- 0.4) x 10(-25) cm(2) molecule(-1) atm(-1). The temperature dependences of both the water-water and the water-nitrogen continua are shown to be well represented by a model describing the expected behavior of weakly bound binary complexes. Using this model, our data yield dissociation energies of D(e) = (-15.9 +/- 0.3) kJ/mole for the water dimer and D(e) = (-3.2 +/- 1.7) kJ/mole for the water-nitrogen complex. These values are in excellent agreement with recent theoretical predictions of D(e) = -15.7 kJ/mole (water dimer) and D(e) = -2.9 kJ/mole (water-nitrogen complex), as well as the experimentally determined value of D(e) = (-15.3 +/- 2.1) kJ/mole for the water dimer obtained by investigators employing a thermal conductivity technique. Although there is reasonably good agreement with the magnitude of the continuum absorption coefficients, the agreement on temperature dependence is less satisfactory. While our results are suggestive of the role played by water dimers and water complexes in producing the infrared continuum, the uncertain spectroscopy of the water dimer in this spectral region prevents us from making a firm conclusion. In the meantime, empirical models of water vapor continuum absorption, essential for atmospheric radiative transfer calculations, should be refined to give better agreement with our low-uncertainty continuum absorption data.
Collapse
Affiliation(s)
- John G Cormier
- Chemical Sciences and Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.
| | | | | |
Collapse
|
44
|
Vorsa V, Dheandhanoo S, Ketkar SN, Hodges JT. Quantitative absorption spectroscopy of residual water vapor in high-purity gases: pressure broadening of the 1.39253-microm H2O transition by N2, HCl, HBr, Cl2, and O2. Appl Opt 2005; 44:611-619. [PMID: 15726959 DOI: 10.1364/ao.44.000611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We determined the respective pressure-broadening coefficients of HCl, HBr, Cl2, and O2 (expressed relative to that of the reference gas N2) for the (v1,v2,v3)J(Ka,Kc) = (0,0,0)3(0,3) --> (1,0,1)2(0,2) rovibrational transition of H2 16O that occurs at 1.39253 microm. The experiment used a continuous-wave cavity ring-down spectroscopy analyzer to measure the peak absorption losses as a function of added moisture concentration. The measured pressure-broadening coefficients for HCl, HBr, Cl2, and O2 are, respectively, 2.76, 2.48, 1.39, and 0.49 times that of the N2 pressure-broadening coefficient, and detection limits for water vapor range from 0.22 nmol mol(-1) for O2 matrix gas to 2.3 nmol mol(-1) for HBr matrix gas. The degradation of the detection limit (relative to the N2 matrix gas) is ascribed to a pressure-broadening-induced reduction in peak absorption cross section and to elevated background loss from the matrix gas.
Collapse
Affiliation(s)
- Vasil Vorsa
- Air Products and Chemicals, Inc, Allentown, Pennsylvania 18195, USA.
| | | | | | | |
Collapse
|
45
|
Hovde DC, Hodges JT, Scace GE, Silver JA. Wavelength-modulation laser hygrometer for ultrasensitive detection of water vapor in semiconductor gases. Appl Opt 2001; 40:829-839. [PMID: 18357063 DOI: 10.1364/ao.40.000829] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Water vapor is measured by use of a near-infrared diode laser and wavelength-modulation absorption spectroscopy. Humidity levels as low as 5 nmol/mol [1 nmol/mol = 1 ppb (1 ppb equals 1 part in 10(9))] of water vapor in air are measured with a sensitivity of better than 0.2 nmol/mol (3varsigma). The sensitivity, linearity, and stability of the technique are determined in experiments conducted at the National Institute of Standards and Technology, Gaithersburg, Maryland, by use of the low frost-point humidity generator over the range from 5 nmol/mol to 2.5 mumol/mol of water vapor in air. The pressure-broadening coefficients for water broadened by helium [0.0199(6) cm(-1) atm(-1) HWHM] and by hydrogen chloride [0.268(6) cm(-1) atm(-1) HWHM] are reported for the water line at 1392.5 nm.
Collapse
|
46
|
Abstract
We discuss the use of single-mode cavity ringdown spectroscopy with pulsed lasers for quantitative gas density and line strength measurements. The single-mode approach to cavity ringdown spectroscopy gives single exponential decay signals without mode beating, which allows measurements with uncertainties near the shot-noise limit. The technique is demonstrated with a 10-cm-long ringdown cavity and a pulsed, frequency-stabilized optical parametric oscillator as the light source. A noise-equivalent absorption coefficient of 5 x 10(-10) cm(-1) Hz(-1/2) is demonstrated, and the relative standard deviation in the ringdown time (sigma(tau)/tau) extracted from a fit to an individual ringdown curve is found to be the same as that for an ensemble of hundreds of independent measurements. Repeated measurement of a line strength is shown to have a standard deviation <0.3%. The effects of normally distributed noise on quantities measured using cavity ringdown spectroscopy are discussed, formulas for the relative standard deviation in the ringdown time are given in the shot- and technical-noise limits, and the noise-equivalent absorption coefficient in these limits are compared for pulsed and continuous-wave light sources.
Collapse
Affiliation(s)
- R D van Zee
- Chemical Science and Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899-8364, USA
| | | | | |
Collapse
|
47
|
|
48
|
Lock JA, Hodges JT. Far-field scattering of a non-Gaussian off-axis axisymmetric laser beam by a spherical particle. Appl Opt 1996; 35:6605-6616. [PMID: 21127684 DOI: 10.1364/ao.35.006605] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Experimental laser beam profiles often deviate somewhat from the ideal Gaussian shape of the axisymmetric TEM(00) laser mode. To take these deviations into account when calculating light scattering of an off-axis beam by a spherical particle, we use our phase-modeling method to approximate the beam-shape coefficients in the partial wave expansion of an experimental laser beam. We then use these beam-shape coefficients to compute the near-forward direction scattering of the off-axis beam by the particle. Our results are compared with laboratory data, and we give a physical interpretation of the various features observed in the angular scattering patterns.
Collapse
|
49
|
Abstract
We have investigated the effects of laser bandwidth on quantitative cavity ring-down spectroscopy using the (r)R transitions of the b(ν = 0)?X(ν = 0) band of molecular oxygen. It is found that failure to account properly for the laser bandwidth leads to systematic errors in the number densities determined from measured ring-down signals. When the frequency-integrated expression for the ring-down signal is fitted and measured laser line shapes are used, excellent agreement between measured and predicted number densities is found.
Collapse
|
50
|
Lock JA, Hodges JT. Far-field scattering of an axisymmetric laser beam of arbitrary profile by an on-axis spherical particle. Appl Opt 1996; 35:4283-4290. [PMID: 21102837 DOI: 10.1364/ao.35.004283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Experimental laser beam profiles often deviate somewhat from the ideal Gaussian shape of the TEM(00) laser mode. In order to take these deviations into account when calculating light scattering, we propose a method for approximating the beam shape coefficients in the partial wave expansion of an experimental laser beam. We then compute scattering by a single dielectric spherical particle placed on the beam's axis using this method and compare our results to laboratory data. Our model calculations fit the laboratory data well.
Collapse
|