Optical frequency comb Fourier transform spectroscopy of 14N216O at 7.8 µm. (September 2021)

• Record Type: Journal Article
• Authors: Hjältén, Adrian; Germann, Matthias; Krzempek, Karol; Hudzikowski, Arkadiusz; Głuszek, Aleksander; Tomaszewska, Dorota; Soboń, Grzegorz; Foltynowicz, Aleksandra
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 271(2021)
• Publication Date: 2021-09
• Subjects: Nitrous oxide -- High-resolution spectroscopy -- Optical frequency comb -- Fourier transform spectroscopy; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2021.107734
• Languages: English
• ISSNs: 0022-4073

Abstract

Highlights: Frequency comb Fourier transform spectroscopy at 7.8 µm based on a compact difference frequency generation source. High-precision measurements of the ν1 fundamental band and the ν1 + ν2 – ν2 hot band of 14 N2 16 O. Line positions with uncertainties of the order of 90-600 kHz. Abstract: We use a Fourier transform spectrometer based on a compact mid-infrared difference frequency generation comb source to perform broadband high-resolution measurements of nitrous oxide, 14 N2 16 O, and retrieve line center frequencies of the ν1 fundamental band and the ν1 + ν2 – ν2 hot band. The spectrum spans 90 cm −1 around 1285 cm −1 with a sample point spacing of 3 × 10 −4 cm −1 (9 MHz). We report line positions of 72 lines in the ν1 fundamental band between P(37) and R(38), and 112 lines in the ν1 + ν2 – ν2 hot band (split into two components with e/f rotationless parity) between P(34) and R(33), with uncertainties in the range of 90-600 kHz. We derive upper state constants of both bands from a fit of the effective ro-vibrational Hamiltonian to the line center positions. For the fundamental band, we observe excellent agreement in the retrieved line positions and upper state constants with those reported in a recent study by AlSaif et al. using a comb-referenced quantum cascade laser [J Quant Spectrosc Radiat Transf, 2018;211:172-178]. We determine the origin of the hot band with precision one order of magnitude better than previous work based on FTIR measurements by Toth [http://mark4sun.jpl.nasa.gov/n2o.html ], which is the source of the HITRAN2016 data for these bands.