Li Mingquan, Chen Mingjun, Cheng Jian, Xiao Yong, Jiang Wei
Center for Precision Engineering, Harbin Institute of Technology, Harbin, China.
Appl Opt. 2013 May 20;52(15):3451-60. doi: 10.1364/AO.52.003451.
Mid-frequency waviness and subsurface crack are two fundamental factors that damage KH(2)PO(4) (KDP) crystal processed by ultraprecise fly cutting. In this paper, the motif theory and the Fourier model method are used to analyze the influence of the two factors on the laser-induced damage threshold (LIDT) of KDP. Research results indicate that the modulation degrees increase nearly linearly when the waviness amplitude and subsurface crack depth increase, and, meanwhile, the LIDT tends to decrease. The two factors have different effects during different stages of KDP failure. The mean amplitudes of waviness and subsurface damage depth have similar changing regulations with different feeds. From the machining perspective, we need not necessarily know which is more dangerous, because when one factor is controlled, the other one will also be restrained at the same time. In general, smaller feed and cutting depth are benefits for improving the LIDT of KDP.
中频波纹度和亚表面裂纹是损害超精密飞切加工的磷酸二氢钾（KDP）晶体的两个基本因素。本文采用基元理论和傅里叶模型方法分析了这两个因素对KDP晶体激光诱导损伤阈值（LIDT）的影响。研究结果表明，随着波纹度幅值和亚表面裂纹深度的增加，调制度近似呈线性增加，同时LIDT趋于降低。这两个因素在KDP晶体破坏的不同阶段具有不同的作用。波纹度平均幅值和亚表面损伤深度随进给量的变化规律相似。从加工角度来看，我们不一定需要知道哪个因素更危险，因为当一个因素得到控制时，另一个因素也会同时受到抑制。一般来说，较小的进给量和切削深度有利于提高KDP晶体的LIDT。
