Submillimeter laser using formic acid vapor pumped with carbon dioxide laser radiation

The stimulated emission from formic acid molecules was observed for the first time in the submillimeter range. The pumping source was a frequency-tunable CO₂ laser. The cw power of the submillimeter radiation ranged from tens of microwatts to several milliwatts when the pumping power was up to 7 W. The stimulated emission was observed at 22 wavelengths ranging from 250 to 750 μ.