High resolution infrared spectroscopy using a spin-flip Raman laser: the bands of carbonyl sulphide near 1890 cm–1

Abstract

The infrared combination band of carbonyl sulphide at 1892 cm^–1 due to (1 2⁰ 0)â†�(0 0⁰ 0) forms a useful test spectrum for commissioning a spin-flip Raman laser. In addition to those from the ground state, lines which could be attributed to the hot band (1 3¹ 0)â†�(0 1¹ 0) with l-type doubling were observed. An analysis was performed assuming lower state constants from microwave values. The transition centre, the rotational constant and the centrifugal distortion constant for the (1 3¹ 0)^e state were found to be 1891.694(2) cm^–1, 6087.03(12) MHz and 1.24(6) kHz, and for the (1 3¹ 0)^f state to be 1891.693(2) cm^–1, 6100.22(11) MHz and 1.28(5) kHz respectively.