光学元件亚表面缺陷的全内反射显微检测

Total internal reflection microscopy:a subsurface defects identification technique in optically transparent components

光学元件亚表面缺陷的有效检测已成为高阈值抗激光损伤光学元件制造的迫切要求。基于全内反射照明原理开展了全内反射显微技术检测光学元件亚表面缺陷的实验研究。结果表明:全内反射显微技术可有效检测光学元件亚表面缺陷;入射光偏振态和入射角度会影响元件内界面下不同深度处驻波形式照明强度的分布,对于可见度发生明显改变的微小缺陷点能衡量出其一定的深度尺寸范围;利用显微镜精密调焦对界面下一定深度处缺陷成像,可知缺陷点的位置深度。

Available test technique for the subsurface defects to be applied in optical process has become an urgent require- ment of the manufacture of optics with high resistance to damage. Based on theory of total internal reflection illumination, the research on total internal reflection microscopy（TIRM） technique is done experimentally. It is proved that the TIRM technique for the detection of the subsurface defects is valid, the transformation of the polarization or the incident angle will affect the illumination distribution below the interface, hence the change in visibility of the tiny defects can be used to evaluate the size of the defects in the depth direction. The depth of the subsurface defects can also be gained according to the focusing distance of the microscopy from the interface to the defects.