Temperature-dependent high resolution absorption cross sections of propane

Beale, Christopher; Hargreaves, Robert J.; Bernath, P. F.

doi:10.1016/j.jqsrt.2016.06.006

Cited by 20 publications

(3 citation statements)

References 39 publications

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“…where the cell length was L = 13 cm, the propane pressure was p = 4.5 Torr, and the room temperature was T = 293 K. As shown in Figure (c-d), the measured cross-section agrees well with a recent high-resolution FTS measurement [35], capturing both a broad absorption envelope and many narrow features. The statistical uncertainty of the cross-section scales inversely with the signal strength of the raw spectra; it is ~5 10 cm 2 molecule -1 around 2960 cm -1 and ~10 cm 2 molecule -1 around 2900 cm -1 .…”

Section: Propane Absorption Cross-sectionsupporting

confidence: 83%

“…The measured cross-section was shifted by a constant offset to be zero around 2700 cm -1 where no absorbers are present. The DCS measured crosssection, spanning 140 cm -1 and 21,000 comb modes, compares well to a high-resolution FTS measurement by Beale et al [35] (red line), with their difference (gray line) flat to within 5 10 cm molecule (standard deviation) other than at 2967 cm -1 where there is full extinction in the DCS spectrum. d) Detail of the propane cross-section, showing its highly structured nature and excellent agreement between the DCS and high-resolution FTS.…”

Section: Propane Absorption Cross-sectionsupporting

confidence: 82%

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High-coherence mid-infrared dual-comb spectroscopy spanning 2.6 to 5.2 μm

Ycas¹,

Giorgetta²,

Baumann³

et al. 2018

Nature Photon

308

164

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Mid-infrared dual-comb spectroscopy has the potential to supplant conventional high-resolution Fourier transform spectroscopy in applications that require high resolution, accuracy, signal-to-noise ratio, and speed. Until now, dual-comb spectroscopy in the mid-infrared has been limited to narrow optical bandwidths or to low signal-to-noise ratios. Using a combination of digital signal processing and broadband frequency conversion in waveguides, we demonstrate a midinfrared dual-comb spectrometer that can measure comb-tooth resolved spectra across an octave of bandwidth in the mid-infrared from 2.6-5.2 µm with sub-MHz frequency precision and accuracy and with a spectral signal-to-noise ratio as high as 6500. As a demonstration, we measure the highly structured, broadband cross-section of propane (C3H8) in the 2860-3020 cm -1 region, the complex phase/amplitude spectrum of carbonyl sulfide (COS) in the 2000 to 2100 cm -1 region, and the complex spectra of methane, acetylene, and ethane in the 2860-3400 cm -1 region.Mid-infrared spectroscopy is a powerful technique for the multispecies detection of trace gases with applications ranging from the detection of hazardous materials, to environmental monitoring and industrial monitoring. Compared to the near-infrared, where laser sources are more plentiful, the techniques for measuring mid-infrared spectra are more limited. Mid-infrared spectra are most commonly acquired by Fourier transform spectroscopy (FTS), which provides accurate and high resolution spectra but requires a scanning delay arm and blackbody source leading to large instruments and long acquisition times. Dual-comb spectroscopy (DCS) is a high-performance alternative to conventional FTS providing high resolution, absolute frequency accuracy, fast acquisition times, long interaction lengths, broad bandwidth coverage, and high signal-to-noise ratio [1,2]. The advantages of speed and long path length are of particular relevance to non-laboratory applications, for example in open-path atmospheric monitoring or industrial process monitoring [3][4][5][6]. However, up until now, DCS has only been demonstrated with its full panoply of advantages in the near-infrared, from ~ 1 to 2 µm [7-10]. The near-infrared has much more limited applications compared to the mid-infrared since molecular crosssections are typically 1000 times weaker, if they exist at all. DCS in the mid-infrared has indeed been actively pursued [11][12][13][14][15][16][17][18][19][20][21][22][23][24], yet it is not competitive with high-resolution conventional FTS, limited by the coherence and/or the bandwidth of mid-infrared comb sources.Quantitative broadband mid-infrared DCS requires addressing strong overlapping requirements on the underlying mid-infrared frequency combs: they must produce broad and relatively flat optical spectra while maintaining mutual coherence over the measurement time. Without coherence, adjacent comb teeth blend together, sacrificing orders of magnitude in spectral resolution and obscuring both the frequency and amplit...

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Section: Propane Absorption Cross-sectionsupporting

confidence: 83%

Section: Propane Absorption Cross-sectionsupporting

confidence: 82%

High-coherence mid-infrared dual-comb spectroscopy spanning 2.6 to 5.2 μm

Ycas¹,

Giorgetta²,

Baumann³

et al. 2018

Nature Photon

308

164

View full text Add to dashboard Cite

show abstract

“…The IR bands have also been used for other satellite, aircraft and ground-based telescopic observations [3,4]. Intensity, temperature and collision broadening studies have also been done recently to aid in the astrophysical studies [14][15][16]. The interstellar medium where new solar systems exist or are forming is also a place to expect to find propane since other organic molecules have been detected by these same observing methodologies [17].…”

Section: Introductionmentioning

confidence: 99%

First high-resolution infrared spectra of 2–13C-propane: Analyses of the ν26 (B2) c-type and ν9 (A1) b-type bands

Daunt

Grzywacz

Western

et al. 2020

Journal of Molecular Structure

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This paper presents the first high resolution (Δν = 0.00096 cm −1) IR investigation of 2-13 C-propane. Spectra of the ν9(A1) CCC skeletal bending mode near 336.767 cm −1 (a b-type band) and the ν26(B2) methylene (CH2) rocking mode near 746.614 cm −1 (a c-type band) were recorded at the Canadian Light Source (CLS) synchrotron. The spectra were assigned both traditionally and with the aid of the PGOPHER program. As only limited microwave data are available for this molecule the present data was used to determine a new set of ground state constants that included centrifugal distortion terms. Upper state constants for both bands have been determined that provide a good simulation of the spectra. The analysis also included the strong a-type Coriolis resonance between the ν26 and 2ν9 states that causes strong perturbation-allowed transitions to appear in the spectrum. Lines of the 2ν9-ν9 hot band were also assigned and included in our analysis of the bending region. This data will be useful in identifying isotopic propane lines in Titan and other astrophysical objects.

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