Radial characteristics of the stimulated emission of copper-vapor lasers

Abstract

Copper-vapor lasers are currently under investigation with the definite aim of increasing the efficiency and mean power of such lasers. One way of doing this is to increase the repetition frequency of the pulse discharge and increase the volume of the active medium. However, if the interval between the pulses is reduced, cumulative effects begin to play a part in determining the state of the active medium before a new pulse. The main such effects are evidently the accumulation of heat, electrons, and metastable atoms. Ultimately, they reduce the pulse power and mean power of the laser. The reduction is characterized by the fact that the power of the laser emission decreases primarily in the center of the tube, and the transverse structure of the beam acquires an annular shape. Moreover, with increasing diameter of the working channel, these features are manifested at lower repetition frequencies. [1]. The present paper gives experimental data on this phenomenon and an attempt to explain it on the basis of the radial characteristics of the active medium.