Emission spectra of a pulsed electron-beam-controlled CO laser with selective and nonselective resonators

For the fust time an experimental investigation was made of the time evolution, in the free-lasing regime, of the full vibrational-rotational structure of the emission spectrum of a pulsed cryogenically cooled electronbeam- controlled CO laser, using both broad-band nonselective and selective (with a diffraction grating as the nontransmitting mirror) resonators. Lasing was obtained in 15 vibrational bands. The emission spectra were found to be irregular and nonmonotonically varying with time. The specific output energy averaged 1–2 J·liter^–1·amagat^–1 for an individual vibrational-rotational line. A qualitative explanation of the obtained results is based on a relaxation model for the excitation of the vibrational levels of an electron-beamcontrolled CO laser.