Q-SWITCH REGIME OF 3-MU-M ER-YAG LASERS

A mathematical model, based exclusively on spectroscopic data concerni ng radiative, nonradiative, and energy transfer processes, is proposed and used to simulate the Q-switch regime of a 3-mu m Er:YAG laser, Th e connection between the main energy transfer mechanisms that make pos sible generation on the self-saturated transition I-4(11/2) --> I-4(13 /2) (upconversion from I-4(13/2) and I-4(11/2) and cross relaxation fr om S-4(3/2)) and the giant pulse characteristics are discussed. The ra diative as well as nonradiative losses during optical pumping and gian t pulse generation are defined and evaluated. A particular attention i s given to the frustrated total internal reflection (FTIR) Q-switch wh ich demonstrated real qualities for 3-mu m erbium lasers. The reasons responsible for experimental performances of Q-switched Er:YAG lasers inferior to those predicted by the mathematical modeling are analyzed.