Patent ID: 7327769

Claim:
A laser system comprising: a local oscillator generating a reference laser beam at a fixed output frequency; a laser including a resonant cavity defined by at least two mirrors and wherein one of the mirrors is coupled to a position controller for adjusting the position of said one mirror to control the length of the cavity, said laser including a Q-switch which is repeatedly activated to change the cavity between a high loss and a low loss state causing pulses of laser radiation to be generated; optics for directing the reference laser beam into the resonant cavity of the laser; a detector for monitoring intensity of the pulses generated by the laser; and a control circuit receiving the output from the detector and monitoring the rise time of the laser pulse emitted from the laser after each activation of the Q-switch and generating a control signal supplied to said position controller to drive the mirror to a position which minimizes the rise time of the detected pulses and thereby lock the output frequency of the laser to the frequency of the local oscillator.