10min:

N. NISHIMIYA, T. YUKIYA AND M. SUZUKI, Tokyo Polytechnic University, System Electronics and Information Technology, Iiyama 1583, Atsugi-City, 243-0297 Kanagawa, Japan.

\hspace3emDoppler limited vib-rotational spectrum of the A³ _1u X^{1 +}_g system of ⁷⁹Br₂, ⁸¹Br₂, and ⁷⁹Br⁸¹Br have been measured using a titanium sapphire laser. We adapted the two-tone modulation method to detect the absorption spectrum ¹. Measurements were made at room temperature in the region of 13000 -- 13700 cm^-1 and at 150^\circC in the region 12000 -- 13000 cm^-1, as determined using a wavelength meter (Burleigh WA-1500) calibrated to the two-photon spectrum of Rb at 778 nm. The wavenumber accuracy measurement was estimated to be 0.005 cm^-1. About 10,000 lines of P, Q, and R-branches from 20 \leq J \leq 100 were assigned and spectroscopic constants of ⁷⁹Br⁸¹Br for v' = 4 - 9 were determined using a global least-squares fit to all lines of the three isotopic species by taking the reduced mass ratios into consideration. The details of the results will be presented.

\underline\makebox[8cm]

1. D.E.Cooper and R.E.Warren, \sl J.Opt.Soc.Am.B, 4, 470 (1987).