Single pulse switchout system for a passively mode-locked Q-switched Nd:YAG laser

Abstract

A new optical switchout device for a passively mode‐locked Q‐switched laser is presented. This device can switch out a single pulse with energy at a preset level. The stability of the switched out single‐pulse energy is greater than the input pulse train. This is achieved by means of a high speed comparator and avalanche transitor chains. A single pulse of ±13% energy stability is obtained from the pulse train of our Nd:YAG laser oscillator with a ±25% fluctuation. The maximum repetition frequency of 2 kHz is sufficient not only for this kind of laser but also for other applications. The life of the avalanche transistors used here is more than one million shots. The possibility of further improvements in output stability is also discussed.