Rapid, Broadband Spectroscopic Temperature Measurement Of Co2 Using Vipa Spectroscopy

Abstract

Time-resolved spectroscopic temperature measurements of a sealed carbon dioxide sample cell were realized with an optical frequency comb combined with a two-dimensional dispersive spectrometer. A supercontinuum laser source based on an erbium fiber mode-locked laser was employed to generate coherent light around 2000 nm (5000 cm(-1)). The laser was passed through a 12-cm-long cell containing CO2, and the transmitted light was analyzed in a virtually imaged phased array-based spectrometer. Broadband spectra spanning more than 100 cm(-1) with a spectral resolution of roughly 0.075 cm(-1) (2.2 GHz) were acquired with an integration period of 2 ms. The temperature of the CO2 sample was deduced from fitting a modeled spectrum to the line intensities of the experimentally acquired spectrum. Temperature dynamics on the timescale of milliseconds were observed with a temperature resolution of 2.6 K. The spectroscopically deduced temperatures agreed with temperatures of the sample cell measured with a thermistor. Potential applications of this technique include quantitative measurement of carbon dioxide concentration and temperature dynamics in gas-phase chemical reactions(e.g., combustion) and plasma diagnostics.

Time-resolved spectroscopic temperature measurements of a sealed carbon dioxide sample cell were realized with an optical frequency comb combined with a two-dimensional dispersive spectrometer. A supercontinuum laser source based on an erbium fiber mode-locked laser was employed to generate coherent light around 2000 nm (5000 cm(-1)). The laser was passed through a 12-cm-long cell containing CO2, and the transmitted light was analyzed in a virtually imaged phased array-based spectrometer. Broadband spectra spanning more than 100 cm(-1) with a spectral resolution of roughly 0.075 cm(-1) (2.2 GHz) were acquired with an integration period of 2 ms. The temperature of the CO2 sample was deduced from fitting a modeled spectrum to the line intensities of the experimentally acquired spectrum. Temperature dynamics on the timescale of milliseconds were observed with a temperature resolution of 2.6 K. The spectroscopically deduced temperatures agreed with temperatures of the sample cell measured with a thermistor. Potential applications of this technique include quantitative measurement of carbon dioxide concentration and temperature dynamics in gas-phase chemical reactions(e.g., combustion) and plasma diagnostics.