Pulse evolution and mode selection characteristics in a TEA-CO 2 laser perturbed by injection of external radiation

Abstract

A grating-tunable TEA-CO 2 laser with an unstable resonator cavity, modified to allow injection of cw CO 2 laser radiation at the resonant transition line by means of an intracavity NaCl window, has been used to study the coupling requirements for generation of single frequency pulses. The width and shape of the mode selection region, and the dependence of the gain-switched spike buildup time and the pulse shapes on the intensity and detuning frequency of the injected radiation are reported. Comparisons of the experimental results with previously reported mode selection behavior are discussed.