Development of a high-energy Q-switched slab laser for targeting designation

A high-energy electro-optically Q-switched Nd:YAG laser at 1064 nm is presented, which can provide the largest output pulse energy of 196 mJ with the pulse duration of 12 ns and the repetition rate up to 30 Hz. The crossed-Porro resonator and zigzag slab gain medium are utilized to increase the misalignment tolerance of resonator up to 2 arcmin and minimize the divergence angle of laser beam to 1.7 mrad. We control the initial population inversion by intra-cavity quasi-CW lasing to limit maximum output pulse energy, and the excess pump energy is used to overcome performance degradation dependence on environmental temperature. As a result, a nearly constant output pulse energy can be obtained over a wide operating temperature range.