Spatial heterodyne spectroscopy for long-wave infrared: optical design and laboratory performance

Abstract

<p>Spatial heterodyne spectroscopy for long-wave infrared identifies an ozone line near 1133 cm(-1) (about 8.8 mu m) as a suitable target line, the Doppler shifts of which are used to retrieve stratosphere wind and ozone concentration. The basic principle of Spatial Heterodyne Spectroscopy (SHS) is elaborated. Theoretical analyses for the optical parameters of spatial heterodyne spectroscopy are deduced. The optical system is designed to work at 160 K and to maximize the field of view (FOV). The optical design and simulation is carried on to fulfill the requirement. The principle prototype was built and a frequency-stable laser was used to conduct the experiment. Result shows that the designed interferometer can meet the requirement of spectral resolution (0.1 cm(-1)) and that the spatial frequency of fringe pattern is consistent with the theoretical value at normal temperature and pressure.</p>