Buffer-gas pressure broadening for the (3 00 1)III ← (0 0 0) band of CO2 measured with continuous-wave cavity ring-down spectroscopy

Abstract

Buffer-gas pressure broadening for the (3 0⁰ 1)_III ← (0 0 0) band of CO₂ in the 1600 nm region was investigated with continuous wave cavity ring-down spectroscopy within the temperature range 263–326 K. The measured absorption profiles were analyzed with Voigt functions. Pressure broadening coefficient, γ(gas), and the temperature dependent parameter (broadening exponent), n, were determined for a variety of buffer gases: N₂, O₂, He, Ne, Ar, Kr and Xe. γ(air) values estimated subsequently are 0.096(2) for R(0), 0.085(5) for P(8), 0.075(2) for P(16), 0.070(4) for P(26), and 0.069(2) for P(38) in units of cm⁻¹ atm⁻¹, where numbers in parentheses are one standard deviation in units of the last digits quoted. n(air) values are 0.77(4) for R(0), and 0.73(11) for P(8).