Two-dimensional optical measurement techniques based on optical birefringence effects

Abstract

Some dielectric materials become birefringent when subjected to an external force, such as an electric field or a mechanical force. For more than a decade, our research group has been engaged in developing two-dimensionaloptical measurement techniques for the dynamic measurement of charge distributions on a dielectric surface using the electro-optic Pockels effect, the dynamic measurement of electrical field distributions in a liquid using the electro-optic Kerr effect, and the measurement of birefringence vector distributions in plastic plates using the photoelastic effect. The system nonuniformity and the system reliability are the inevitable problems in two-dimensional measurement systems, and make two-dimensional measurements quite different from point measurements. The common image-processing techniques that have been specially developed to overcome these problems are analyzed and summarized; detailed mathematical analysis is avoided.