Methods for reducing stress birefringence in cadmium telluride electro-optic modulators

Publisher Website
Google Scholar
Abstract
By studying the static birefringence pattern of cadmium telluride electro-optic modulator crystals after fabrication, it has been determined that standard fabrication processes induce excessive stress birefringence. This stress birefringence is produced during the grinding stage of fabrication. Two methods for removing this birefringence have been explored: (1) mechanical polishing of the sides of the crystal to an optical finish, and (2) chemical etching of the sides of the crystal with a 5% bromine solution. Both methods reduced the static birefringence of the crystal. The stress birefringence pattern can be recreated by grinding the sides of the crystal with 9 μm polishing grit.