KDP晶体表面残留磁流变抛光液清洗技术研究

Study on cleaning of residual from magnetorheological finishing （MRF） of potassium dihydrogen phosphate（KDP） crystal surface

磷酸二氢钾（KDP）晶体是一种非常优良的非线性光学晶体材料，在强激光系统中有着重要应用。但其理化性质特殊，加工高表面质量的元件难度很大。目前研究认为磁流变抛光技术能够获得高精度的KDP晶体表面，但是该加工过程带入的表面残留如不清除，会大大降低元件的性能。提出了一种针对磁流变抛光后续的KDP的清洗技术，设计了含水活性清洗液，结合超高频超声作用共同去除KDP表面残留。光学显微镜和白光干涉仪分析表明，该技术较好地去除了表面残留，并且晶体表面粗糙度有所降低。拉曼光谱和激光干涉仪测试表明，清洗前后KDP表面化学结构和面形精度一致。该研究获得了较为满意的结果，说明该方法是一种有应用前景的KDP超精密清洗方法。

KDP is a type of excellent nonlinear single crystal electro-optical material, which is used in high-energy laser systems. However, KDP is extremely difficult to be finished for its particular physical and chemical properties. Magnetorheological finishing （MRF） is considered to be an effective processing method for finishing KDP to high precision at present. But the performance of KDP would decrease obviously if the residual contamination remained after finishing. An active cleaning agent with high- frequency ultrasound technology was put forward to solve the problem. Microscope and white-light- interferometer were employed to assess the effects of cleaning process on KDP surface. The results show that the residual contamination is removed availably, and the surface roughness is improved as well. Additionally, the Raman spectral and laser interferometer analysis indicates that crystal structure and surface accuracy of KDP remain unchanged after cleaning. These conclusions prove that the cleaning method achieves desired result and exhibits a promising prospect of KDP cleaning.