Spectroscopic measurements on the laser emission from discharges in compounds of hydrogen, carbon, and nitrogen

A pulsed electrical discharge through dimethylamine or a mixture of methane and ammonia at low pressure has produced stimulated emission at twenty-one wavelengths between 71 and 373 μm. Ten of the lines in the range 71 to 116 μm are new; some of the others are identical to those produced with the so-called cyanide laser. The radiation was analyzed with a spectroscopic system comprising a reflection grating monochromator, a Michelson interferometer, and two fast-response detectors operated at 4.2°K. The wavelengths of all the lines were measured to a few parts in 10⁵. Accurate wavelengths are also reported for four new lines from a mixture of methane and¹⁵N-ammonia, and four lines from a mixture of deuterated methane and deuterated ammonia. Observations are described confirming that the presence of a hydrogen isotope is necessary for laser emission to occur. The wavelengths obtained for the 310-, 311-, 337-, and 373-μm lines agree closely with the assignment to HCN by Lide and Maki.