Far-infrared laser emission in gas discharges containing boron trihalides

Laser emission has been observed at 54 wavelengths between 11 and 41 μ in pulsed electrical discharges in BF
3
, BCl
3
, and BBr
3
. The emission wavelengths have been measured and the time behavior of the lines studied. Lasing in each of the gases produces total peak powers on the order of 10 to 100 mW. The addition of N
2
, He, or H
2
O to the discharge is found to have considerable effect on the peak powers of various lines and on the total energy emitted. The observed wavelengths are consistent with pure rotational transitions in HF, HCl, and HBr. Some short wavelength lines in the
1.5-6 \mu
region are also observed but do not appear to be associated directly with the far-infrared emissions.