@inproceedings{639e1294a9704c41b1bf44e5ab1879df,
title = "Open-path remote sensing for multi-species gas detection using a broadband optical parametric oscillator",
abstract = "We demonstrate path-integrated simultaneous concentration measurements of water, methane and ethane, measuring spectra across the 3.1-3.5-μm range using 0.05 cm-1 resolution Fourier-transform spectroscopy in-line with an ultrafast optical parametric oscillator and a simple, non-compliant target. Illumination spectra were extracted from a fitting procedure which simultaneously minimized the rms error between the experimental spectrum and a synthetic spectrum calculated from the envelope and a fitted mixture of PNNL or HITRAN absorbance data for water, methane and ethane. Simultaneous methane, ethane and water measurement at 30-m range were initially performed. Indoor measurements launched light from the OPO through a 20-cm-long gas cell containing a 1.5±0.15% ethane-in-air mixture. Light was reflected from a rough Al-foil target. Best-fit concentrations were determined to be 1.15% (water), 1860 ppb (methane) and 1.37 % (ethane). The methane background value is consistent with reported ambient levels. Respective water and ethane values were consistent with the ambient relative humidity. The second experiment demonstrated real-time methane emission measurement at 70-m range. A 2% methane:air mix was released for 100 seconds at a rate of 103 μgs-1 at a distance of 65 m from the OPO. The signal was recorded from a simple target of rough aluminum foil situated 70 m from the OPO, with the beam passing near the emission point. This work demonstrates our ability to extract concentration data from a single spectrum with no need for averaging, which provides a real-time and quantitative monitoring capability.",
keywords = "Broadband, FTIR Spectroscopy, Multi-Species, Open Path Spectroscopy, Optical Parametric Oscillator, Remote Sensing",
author = "Oguzhan Kara and Frazer Sweeney and Marius Rutkauskas and Carl Farrell and Leburn, {Christopher G.} and Reid, {Derryck T.}",
year = "2020",
month = mar,
day = "2",
doi = "10.1117/12.2551702",
language = "English",
isbn = "9781510632936",
series = "Proceedings of SPIE",
publisher = "SPIE",
editor = "Solli, {Daniel R.} and Georg Herink and Serge Bielawski",
booktitle = "Real-Time Measurements, Rogue Phenomena, and Single-Shot Applications V",
address = "United States",
note = "SPIE LASE 2020 ; Conference date: 01-02-2020 Through 06-02-2020",
}