Diode Laser Spectroscopy of H 232S Around 0.82 μm

Abstract

The absorption spectrum of H 2S has been investigated in the range 11 930-12 300 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 3ν 1 + 2ν 3 and 2ν 1 + 3ν 3 bands which are in strong interaction. The rotational 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 levels of (302) with those of (203), as well as weaker anharmonic and Coriolis-type interactions between the levels of (302) and (203) and those 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.