High-resolution measurements of HBr transitions in the first overtone bandusing tunable diode lasers

High-resolution absorption lineshapes of the R(7) and P(2) transitions in t he first overtone (nu = 0-2) band of (HBr)-Br-79 have been recorded at room temperature using a pair of distributed feedback diode lasers operating ne ar 1.95 and 2.00 mu m, respectively. Spectral line intensities and self-bro adening coefficients were determined by fitting the measured spectra (for v arious pressures P = 10-100 Torr) with Voigt profiles and compared with val ues in the literature. Measured line intensities for the P(2) and R(7) tran sitions are similar to 11 and 16% higher than those listed in the HITRAN da tabase, respectively. The measured self-broadening coefficient of the P(2) transition is similar to 14% lower than the value listed in HITRAN. Measure ments of the P(2) lineshapes at low pressure (100 mTorr) were modeled with eight-line Gaussian profiles based on ground state (nu = 0) hyperfine const ants to include the effects of nuclear electric quadrupole interactions. (C ) 2000 Academic Press.