Phase shift polarimetry for non-invasive detection of laser-induced damage

Abstract

The visible light polariscope has been developed to provide high-resolution, full field, stress visualization and analysis in transparent materials. The polariscope images are processed using a four-step phase shifting algorithm to provide qualitative information. The system is calibrated using a disk under compression and then applied to detect the laser induced damage. The capability of the system to locate laser induced damage induced by different power and scanning speed are explored and compared to that using conventional transmission imaging. From the thermal stress, the preliminary information of the laser power and the scanning speed can be obtained.