The behaviour of a 10.6 mu m pulsed spin-flip Raman laser as a spectroscopic source

Abstract

Spectra of ammonia (NH3) gas at about 870 cm-' have been obtained using a pulsed InSb spin-flip Raman laser. Changes in thc temperature of the lnSb crystal were found to produce large changes in the absolute and relative intensities of the absorption lines. The observed line intensities were also found to be dependent on the pump power applied to the InSb crystal. These effccts are attributed to modepulling and mode-hopping in the InSb crystal and to the presence of more than one axial mode. There is also some evidence for the presence of higher-order transverse modes.