High-Resolution Measurements of HBr Transitions in the First Overtone Band Using Tunable Diode Lasers

Abstract

High-resolution absorption lineshapes of the R(7) and P(2) transitions in the first overtone (ν = 0-2) band of H79Br have been recorded at room temperature using a pair of distributed feedback diode lasers operating near 1.95 and 2.00 μm, respectively. Spectral line intensities and self-broadening coefficients were determined by fitting the measured spectra (for various pressures P = 10-100 Torr) with Voigt profiles and compared with values in the literature. Measured line intensities for the P(2) and R(7) transitions are ∼11 and 16% higher than those listed in the HITRAN database, respectively. The measured self-broadening coefficient of the P(2) transition is ∼14% lower than the value listed in HITRAN. Measurements of the P(2) lineshapes at low pressure (100 mTorr) were modeled with eight-line Gaussian profiles based on ground state (ν = 0) hyperfine constants to include the effects of nuclear electric quadrupole interactions. © 2000 Academic Press.