Simulation of transmission characteristics of focused laser inside KDP crystal

Laser producing 3-D microstructures inside KDP crystals is an effective way to suppress the transverse stimulated Raman scattering(TSRS) effect in high power lasers.The transmission characteristics of focused laser inside KDP crystal was simulated to investigate the feasibility of laser making 3-D microstructures and the effects of laser parameters on the machining accuracy,efficiency and success rates.The effects of the focus peak power density,spot distortion and the migration are the main factors affecting the machining accuracy and causing crystal fragmentation.The size and shape of the e-polarization focus will distort and its peak power density decreases rapidly with the increasing of angle between incident laser and crystal optical axis.The results show that the effect of the e-polarization laser will increase the processing efficiency more than twice when the angle is less than 15 and can be neglected in the low-energy or cause crystal fragmentation easily in high-energy when the angle is greater than 30.