We present a simple technique to stabilize the period of the pulses emitted
by passively Q-switched lasers. By slightly modulating the pump diode powe
r, the repetition rate of a Nd3+:YAG laser passively Q switched by Cr4+:YAG
is experimentally shown to reach a time stability of 10(-6) over 10(6) pul
ses. Simulations using a rate-equation model are in close agreement with th
e experiments. (C) 2001 American Institute of Physics.