High repetition rate 300 ps pulses ultraviolet source passively Q:switched microchip laser and a multipass amplifier

Abstract : We demonstrate a new kind of picosecond laser source in the UV at a high repetition rate of 245 kHz, using only passive, compact, and simple elements. This system is based on a microchip laser and a very efficient multipass amplif ier, both pumped with recently developed high-brightness laser diodes. The system has been optimized to deliver, at a high repetition rate, subnanosecond pulses at the wavelength 355 nm with an energy per pulse of close to 1 mJ (38-mW average power). This source is to our knowledge the f irst totally passive 300-ps UV laser source at this high repetition rate.