Taking into account pressure broadening effect of IR pumping laser,the theoretical model of miniature optically pumped submillimeter wave laser was revised according to the density matrix equations. The theoretical calculation results gotten by means of iteration method were in better agreement with the experimental results.
In another way, by using pressure broadening effect of the spectrum and the quasi- continuously tunable SMMW signal can also be obtained by increase the operating gas pressure of the laser and adjusting the length of the cavity.
From the past research work, it has been known that the main mechanisms of spectral lines broadening in the atmospheres of stars are Doppler broadening, spectral lines broadening by rotation and expending, pressure broadening (Stark broadening) , natural broadening, spectral lines broadening in magnetic field, sonic waves and Alfv e n waves broadening, etc.
Firstly, this dissertation focused on two techniques of far infrared laser spectroscopy: FIR-LMR and TuFIR spectroscopy. Secondly, characteristic and analyzing method of far-infrared laser magnetic resonance spectra of halogen-containing radicals were investigated. Finally, the pure rotational spectra of CHF_3, as well as pressure broadening on SO_2 were studied.
Based on theoretical model and calculation method of optical pumped SMMW laser,several problems which should pay attention to in calculation,such as iteration method,resonance characteristic and the feedback property of cavity, Doppler broadening effect and pressure broadening effect etc. ,are presented.