Abstract: The Q-switched laser gating pulses of an acousto-optic Q-switch are synchronized electrically to the phase of the RF signal driving the Q-switch by applying the RF oscillator output signals to the clock input of an integrated circuit D-type flip-flop and the laser gating pulses to the D input of the flip-flop, whereby the leading edge of each output gating pulse from the flip-flop always occurs at a particular place on the RF waveform. In another embodiment, the RF signals are synchronized to the phase of the gating pulses by applying the output of a repetition rate oscillator to the RF oscillator.

Abstract: The initially high amplitude laser output pulses at the start of a string of pulses from a continuously pumped, repetitively, Q-switched Nd:YAG laser are reduced in amplitude by reducing the current to the krypton arc lamp pumping light source by about 5 amperes for a time of about one-half to about one millisecond prior to gating the Q-switch.