FREQUENCY-OFFSETTED CAVITY-LENGTH CONTROL LOOP IN A DIODE-LASER-PUMPED AND ACTIVELY MODE-LOCKED ND-YLF LASER

We have demonstrated a novel stabilization feedback control of an acou sto-optically mode-locked laser. A frequency offset of 6 Hz is maintai ned between the laser repetition rate and the double of the acousto-op tical modulator (AOM) driving frequency, The offset is limited by the response time of the feedback control circuitry, which is estimated to be about 100 ms. In this way, real-time optoelectronic sampling measu rements can be performed by triggering with the AOM driving frequency while sampling with the laser repetition frequency. As a result, time- resolved measurements are greatly simplified when compared with those performed by the delay-line pump-probe technique.