Abstract

A model has been developed to describe the injection control of a pulsed laser amplifier using an unstable resonator.¹ The coupled rate equations for the gain, absorption, and photon flux are numerically integrated allowing the correct treatment of the saturation of both gain and absorption. An extension of this model is reported in which the spatial overlap of the multiple amplifier passes is incorporated into the calculation to more accurately describe the laser saturation processes. In addition, externally located mirrors are modeled by the treatment of the unpumped regions in the cavity and the inclusion of laser cell window losses. This model is used to predict the performance of an electron-beam pumped XeF(C→A) excimer laser over a wide range of experimental configuration using both external and internal optical resonators. The input data for the small signal gain and absorption are derived from experimental net gain and fluorescence measurements and are found to be consistent with the predictions of kinetic calculations. Good agreement is achieved between model predictions and experimental measurements of laser output energy and temporal profile.

© 1989 Optical Society of America