OPTICALLY PUMPED MID-IR LASERS.

Six types of lasers have been used to pump 26 different molecules to produce mid-infrared lasing. These lasers emit between 2. 6 and 35 micrometers. A discussion is presented of many of these optically pumped lasers. It is shown that for optically pumped types, most of the wavelength ranges can be extended and gaps filled in by isotopic substitution in the lasing molecule. Only in the case of high-pressure CO//2-N//2O mixtures has continuous tunability been demonstrated. While at present this must be considered a special case, continuous tuning in other spectral regions should be available in the future.