Abstract

For planetary optical communication applications, reliable, efficient Q-switched solid state lasers which are scalable to the watt level are required. We have investigated the acoustooptic Q-switching of a diode laser end pumped Nd:YAG laser at repetition rates between 1 and 50 kHz. With 400 mW of pump power, average output powers of 88 mW were obtainable. Energy per pulse of 19 µJ at 1-kHz pulse repetition rate and 3.4 µJ at 25-kHz pulse repetition rate was obtained with pulse widths of 18 to 40 ns, respectively. Pulse amplitude stability decreased with increasing repetition rate, becoming unstable beyond 50 kHz. Output pulse stability was also found to depend on the input pump power. Theoretical calculations were involved using a variable order Adams method to numerically solve the rate equations for an end pumped acoustooptically Q-switched Nd:YAG laser. Energy per pulse, average and peak powers, pulse widths, and the optimum time to Q-switch the laser were calculated for various intracavity losses, mirror reflectivities, and pump powers. The Q-switch output energy performance is in good agreement with the theoretical predictions.

© 1989 Optical Society of America