Study of orientation way for large-aperture KDP crystal

In order to obtain higher conversion effectiveness of secondary and triple harmonic.It is very important to accurately determine the orientation of the crystal axis,especially for KDP crystal.However,it all depends on the precise orientation of optical axis of the crystal.In general,the methods of X-ray diffraction or polarized wave interference are used,but these methods have their defects.Here,we employ a Nd:YAG laser beam to accurately inspect the orientation and to find o and e axis of KDP crystal.The experimental arrangement and results have been introduced in this paper.The method have higher measurement accuracy and can used in real-time inspecting.