13CH3F tunable Raman FIR laser

Abstract

It has previously been demonstrated that broad far-infrared tunability can be achieved by pumping ¹²CH3F with a continuously-tunable high-power CO2 pump laser [1]. In those experiments, a ten-atmosphere CO2 pump laser provided 50 nsec output pulses which could be tuned continuously over a 450 GHz range from the CO2 9R10 line to the 9R32 line, inclusively. This frequency range spans the R14 to R26 lines in the V3 band of ¹²CH3F, and with pump pulse energies ranging from 100 to 150 m J, a FIR laser output was obtained over some 85% of the wavelength interval between 220 and 400 μm. At the optimum ¹²CH3F pressure of 25–30 torr, the FIR output pulse energies were of the order of 0.1 mJ. The pump power density threshhold and the tuning curve (FIR output wavelength vs CO2 pump wavelength) were in good agreement with a theoretical model of laser emission via stimulated Raman scattering in CH3F developed by Biron et al [2].