Pulsed gas-discharge lasers

The present review of the investigations of pulsed gas-discharge lasers is based mainly on the literature published up to the middle of 1970. Lasers utilizing transitions in neutral and ionized atoms and electronic transitions in molecules a r e discussed. The attention is concentrated on the systems whose efficiency is likely to be improved. The factors which determine the efficiency and the peak output power are considered. The choice of transitions likely to give high efficiencies and high peak powers is justified. A summary is given of the available information on pulsed gas-discharge lasers of two types: the lasers utilizing transitions from resonance to metastable levels in neutral and ionized atoms and the lasers using electronic transitions in diatomic molecules. The lasers using thallium, copper, and lead vapors and those utilizing transitions in nitrogen molecules are discussed in detail. Practical difficulties encountered in the construction of high-efficiency pulsed lasers are analyzed. A list is given of the transitions in other neutral and ionized atoms and molecules which can be expected to provide high-power pulsed emission. The prospects of utilization of the transitions from a resonance electronic level to the ground state of a molecule a r e stressed. The possibility of advance into the still unmastered vacuum ultraviolet region is discussed. Possible effects of increasing the density of the active gas are considered. Ways of going over from pulsed to continuous-wave emission in collision lasers are analyzed. It is concluded that pulsed gas-discharge lasers offer means for generating high-efficiency (up to 10%) and high-peak-power coherent pulses in a very wide range of wavelengths. It should also be possible to achieve high-efficiency continuous-wave emission in collision lasers operating at short wavelengths.