Tunable diode laser spectroscopy of ethylene oxide near 1693 nm

Trace Measurements of Ethylene Oxide Using Cavity-enhanced Absorption Spectrometry near 3066 cm–1

“…In this paper, we present an ethylene oxide analyzer based on cavity-enhanced absorption spectrometry near 3066 cm -1 that is capable of making real-time measurements with sub-ppb precision. Previously, high-resolution FTIR spectra of ethylene oxide (Sharpe et al, 2004;Johnson et al, 2004) show strong absorption features near 3060 cm -1 and 1270 cm -1 ; however, tunable diode laser absorption spectrometry has only been used (Lytkine et al, 2010) near 5907 cm -1 . This latter work showed a precision of 17 ppm (1σ) using a 63.5 cm cell and extrapolated to a measurement precision of 30 ppb assuming a much longer pathlength (100 meters) and 10x reduction in noise using wavelength modulation spectroscopy.…”

Rapid, broadband spectroscopic temperature measurement of $$\hbox {CO}_2$$ using VIPA spectroscopy

“…Measurements with such systems have been accomplished by rapidly scanning (10 kHz-1 MHz) single-frequency lasers over absorption features in sample gases in harsh environments to measure the linewidth, centroid, and intensity [2][3][4]. One disadvantage of previous spectroscopic temperature measurements is the trade-off of spectral bandwidth for rapid scanning on timescales of under 1 ms.…”

Simultaneous measurement of CO and CO2 at elevated temperatures by diode laser wavelength modulated spectroscopy

“…Vertical cavity surface emitting laser (VCSEL) also provides narrow single frequency emission and has long been considered suitable for such sensing applications [20]. Although it can be tuned continuously over extremely broad spectral intervals (>30 cm À1 ), when referring to gas detection at low pressures, this large current-tuning range of optical frequency is considered as a negative factor because of the corresponding large laser phase noise compared to the small transition line width at low pressures [21,22]. Hence VCSELs are more suitable for gas detection in high-pressure environments.…”