Three-dimensional polarization ray tracing in electro-optic crystals

Electro-optic crystals are extensively utilized to manipulate polarized light. In this paper, a general and accurate three-dimensional polarization ray tracing calculus for characterizing the evolution of polarization state in electro-optic crystals is reported for the first time. The analytical formulas of the parameters describing the propagation properties of the light passing through an electro-optical crystal with an arbitrary incident direction are derived. The partial interference between the divergent light beams is considered in the proposed calculus. Both experiments and calculations on an electro-optic modulator based on a lithium niobate crystal over the azimuth angle of 0∘-360°and the incidence angle of 0∘-3°are presented as an example. The experimental results show very good agreement with the theoretical results.