HIGH-RESOLUTION LASER EXCITATION SPECTROSCOPY OF THE (B)OVER-TILDE(2)SIGMA(-(X)OVER-TILDE(2)SIGMA(+) SYSTEM OF JET-COOLED SROD())

The high-resolution laser excitation spectrum of the 001-000 and 000-0 00 bands of the (B) over tilde(2) Sigma(+)-(X) over tilde(2) Sigma(+) transition of SrOD was recorded. The SrOD molecules were made by pulse d laser ablation of Sr metal followed by reaction with D2O. Sub-Dopple r resolution and rotational cooling were achieved by expansion into va cuum and excitation with a cw dye laser perpendicular to the molecular beam. A molecular linewidth of 200 MHz and the lack of spectral conge stion allowed a Q branch to be detected. Spin-orbit mixing between the (A) over tilde(2) Pi and (B) over tilde(2) Sigma(+) states caused the unusual appearance of a moderate intensity Q branch in a nominally pa rallel (2) Sigma(+)-(2) Sigma(+) transition. From the relative intensi ties of the rotational lines, the ratio of the perpendicular to the pa rallel transition dipole moment was found to be 0.2 to 0.3. (C) 1996 A cademic Press, Inc.