DIODE-LASER SPECTROSCOPY OF H-2 S-32 AROUND 0.82 MU-M

The absorption spectrum of H2S has been investigated in the range 11 9 30-12 300 cm(-1) by means of an externally frequency modulated tunable diode laser and a multipath absorption cell. Approximately 290 lines have been assigned to rovibrational transitions of the 3 nu(1) + 2 nu( 3) and 2 nu(1) + 3 nu(3) bands which are in strong interaction. The ro tational structure of the corresponding excited vibrational states has been satisfactorily reproduced using a Hamiltonian model which takes explicitly into account the strong Coriolis interaction coupling the l evels of(302) with those of (203), as well as weaker anharmonic and Co riolis-type interactions between the levels of(302) and (203) and thos e of (222) and (321). Precise band centers and rotational and coupling constants have been derived and the local mode behavior of the energy levels was clearly observed. (C) 1995 Academic Press, Inc.