EFFECT OF ETCHING AND IMAGING MODE ON THE MEASUREMENT OF SUBSURFACE DAMAGE IN MICROGROUND OPTICAL-GLASSES

Microgrinding of optical glass has been under intensive study recently . Characterization of the subsurface damage (SSD) generated by this pr ocess is very important because it is one of the criteria used to char acterize the quality and efficiency of the microgrinding technique, SE M, as a new method, is applied for a detailed observation of the SSD, Etching with HF solutions of various concentrations is utilized to ope n the subsurface cracks. The etching condition has a significant influ ence on the measured SSD value, Using the SEM method, slightly larger SSD values are obtained compared to those obtained using conventional optical microscopy.