A single mode Nd:YAG Q-switched oscillator with short buildup time

A single longitudinal and transverse mode Nd:YAG laser is described. The unique feature of this laser is the rapid build up time of the output pulse which appears 125 nsec after application of either an optical or electronic trigger pulse, with a jitter of ± 10 nsec. The output is further shuttered to a rectangular pulse of from 1 to 10 nsec duration. Single mode operation is obtained with a two element resonant reflector and a birefringent Lyot filter of calcite. To further aid in frequency selection, the cavity Q is not completely spoiled to allow buildup of quasi-monochromatic radiation before the cavity is switched to high Q. Problems of frequency selection and cavity stability are discussed.