Passively Q-switched 1.064-microm microchip lasers have been constructed from thin pieces of Nd(3+):YAG bonded to thin pieces of Cr(4+):YAG. When pumped with the unfocused 1.2-W output of a fiber-coupled diode, these devices produced 11-microJ pulses of 337-ps duration at a pulse repetition rate of 6 kHz in a single-frequency TEM(00) mode. The peak power of the lasers was in excess of 180 MW/cm(2).

When pumped with a 1-W laser diode, a Tm:YVO(4) microchip laser produced 150 mW of 1.92-µm output in a near-diffraction-limited beam at room temperature. Using a Ti:Al(2)O(3) laser to pump the same device, we showed that reducing the temperature of the Tm:YVO(4) from 20 to -30 °C resulted in no measurable change in threshold and increased the slope efficiency by only 20%.

Nd:YVO(4) microchip lasers have been electro-optically Q switched to produce 12-microJ pulses of 115-ps duration at repetition rates of up to 1 kHz. At a repetition rate of 2.25 MHz, 0.16-microJ pulses with an 8.8-ns duration were obtained.