Abstract

Recently we have reported our development of a mode-locked, Q-switched, cavity- dumped Nd:YAG laser oscillator pumped by diode laser arrays¹ This laser oscillator generated 1.064-μm laser pulses at a 22 Hz repetition rate with the pulsewidth under 100 ps and pulse energy of more than 1 mJ/pulse. Based on this oscillator, we achieved a total energy output about 30 mJ/pulse by adding a pre-amplifier and air amplifier stage. The laser output is near-diffraction limited and therefore provides an ideal pump for nonlinear frequency conversion. We carried out third-harmonic generation (THG) with this laser using LBO nonlinear crystals. We obtained THG efficiencies, with respect to the fundamental input (1.064 pm), of 28% for a Type II LBO crystal and of 25% for a Type I LBO crystal. This laser provides a compact, powerful source of picosecond radiation. Applications include space-borne lidar, medicine, photoproeessing, and pumping tunable picosecond lasers in the UV, visible, and infrared regions. The overall schematic of the laser is shown in Fig. 1.

© 1993 Optical Society of America