Directional prism resonator to improve the output performance of IOPO

The factors that deteriorate output performance of passively Q-switched IOPO include maladjustment of resonator,the instability of the passively Q-switched crystal,and the intensity distribution of intracavity pumping light.By using the directional prism as the reflector of pump resonator,the resonator can be reinforced,the gain distribution becomes even and the pump beam quality is improved.The eye-safe laser is obtained with output energy of 11 mJ,output energy stability of 8%,the wall-plug efficiency of 2.6‰,pulse width of 6.9 ns,and the beam divergence angle of 7 mrad.