A tunable far infrared laser

A continuously tunable far infrared (FIR) laser has been demonstrated; experimental results are presented. A high-pressure (10-12 atm) continuously tunable CO
2
TE laser is used to pump Raman transitions in CH
3
F; the generation of continuously tunable radiation in the
250-300 \mu
m wavelength range is reported. Accurate frequency and bandwidth measurements have been made and the FIR bandwidth in superradiant emission is
\approx4-5
GHz. Consequently, the generation of frequency tunable, subnanosecond pulses in the FIR appears feasible. The generation of tunable laser radiation from 150 to 1000 μm by stimulated Raman scattering should be possible using higher pump intensity and/or other gases.