Spikes in Raman spectrum of miniature optically pumped NH3 FIR laser

In this paper, the semiclassical density matrix equation was solved to calculate the spectral characteristics of V-2:a--sR(0,0) transition in a miniature optically pumped NH3 far infrared laser (mini-NH3-OPFIRL), which was pumped by CO2-10R(6) line. The results of theoretical calculation showed that the spikes in Raman spectrum of V-2:a--sR(0,0) would appear when the operating NH3 gas pressure was higher than a certain critical value or pumping power density was fewer than a certain critical value, which was caused by Raman processes interaction of AC-Stark splitting in our experiment, 298 mu m FIR spetral line of a--sR(0,0) pumped by a TEA-CO2 laser with 10R(6) line was observed hut the spikes could not be observed owing to the limitation of the resolution of the F-P interferometer.