Far-infrared laser oscillations from H2CO

Lasting laser oscillation was obtained from H
2
CO vapor with a longitudinal-flow tube. Ten lasing lines, including six new lines, have been observed in the pressure range of 0.18-0.35 torr. The optimum conditions were 2.5-7.1 kV and 2.5 Hz for excitation voltage and pulse repetition rate, respectively. The pulse shape of the lines was observed by an Ni-W diode.