Birefringence is a fundamental optical property exhibited by materials in which the refractive index varies according to the polarization and propagation direction of incident light. These highly optically anisotropic materials are classified as birefringent crystals. At Atr Crystal, we provide a premium selection of high-performance birefringent crystals—including Yttrium Orthovanadate (YVO4) and Alpha-Barium Borate (α-BBO)—expertly engineered to meet the rigorous demands of your advanced optical systems.