Vol. 19, issue 02-03, article # 7

Abstract:

The nature of physical limitations of the frequency and power characteristics of Сu-vapor laser is considered. It is shown that the processes in the laser discharge circuit determine the power pumped into the gas-discharge through the active component of the discharge impedance, determining the kinetics of the processes during the pump pulse. The development of the processes in the discharge circuit can have aperiodic or oscillatory character. By tuning the laser discharge circuit, i.e., making higher the frequency of its free oscillations, a high pulse repetition frequency (PRF) can be achieved. However, as the frequency of free oscillations increases, the Q-factor of the laser discharge circuit grows while the efficiency of pumping the active medium falls. In the self-heating mode of the Сu-vapor laser operation, this yields a decrease of the mean power of output radiation with the increasing PRF. The maximum mean output power is achieved in maximizing the power deposition into the active medium per single pump pulse, i.e., when the process in the discharge circuit is aperiodic. Consequently, the same process also determines the optimum PRF, at which the power of output laser radiation is maximum, and the cause of its limitation is uniquely related to the prepulse electron concentration.