Investigation of all solid state end-pumped Nd:YAG Q-switched laser

High energy 1064 nm Q-switched laser output is obtained by LD array end pumping Nd:YAG. For different divergence angles of fast axis and slow axis of LD array, cylindrical lens and spherical lens are used for beam shaping of LD array. The laser properties of high energy 1064 nm Q-switched laser with pump energy is investigated with different Nd3+ ion doping concentration and different LD temperature. The results indicate that the extremely high gain formed at the end of the laser is easy to generate self-excited oscillation with the increasing of Nd3+ ion doping concentration and the increasing of LD temperature, which eventually results in the saturation of Q-switched laser pulse energy and makes it difficult to improve further. In view of saturation phenomenon of Q-switched laser output, Nd3+ ion doping concentration and LD temperature adjustment is proposed to reduce the absorption rate of laser medium to the pump light, which provides an effective technical means for obtaining high energy end pumped Q-switched pulsed laser. A 77.8mJ and 10 ns 1064 nm laser is generated with the LD temperature of 20 °C and the Nd3+ ion doping concentration of 0.8%, and the corresponding optical conversion efficiency is 13.9%.