Methods and apparatus of determining a stress-related characteristic of a substrate

Abstract

Apparatus includes a sample holder with a cavity and a plurality of devices configured to hold a curvature of a curved substrate in a fixed configuration. Apparatus includes two prisms with a viewing apparatus of the sample holder configured to translate therebetween. Methods can include disposing the curved substrate in the sample holder, transmitting a first beam, translating the sample holder, and transmitting a second beam. Alternatively, apparatus include a light scattering-polarimetry sub-system configured to emit a first beam to impinge an end surface of coupling prism and detect at least a portion of the first beam impinging the first surface of the coupling prism. The apparatus includes an evanescent prism coupling spectroscopy sub-system configured to emit a second beam to impinge a first surface of the coupling system and detect at least a portion of the second beam impinging the second surface of the coupling prism.