Temperature insensitive high energy Q-switched Nd:YAG slab laser

A temperature insensitive high energy Nd:YAG Q-switched laser operating over a temperature variation range of 35 degrees C is presented. Multi-wavelength (lambda) laser diode (LD) stacks and a hexagon Nd:YAG slab with an effective absorption length of 46 mm are adopted to diminish the output energy fluctuation due to the temperature changing. A couple of crossed Porro prisms are used to form a folded laser cavity with polarization coupled output, and actively Q-switched operation is realized by using a KD*P Pockels cell. Output pulse energy of about 128 mJ is obtained over the temperature range of 10-45 degrees C, corresponding to an optical-to-optical efficiency of 14% and a slope efficiency of 21%. The pulse duration and beam divergence are around 17 ns and 2.8 mrad respectively.