The Yttrium Orthovanadate (YVO4) is a positive uniaxial crystal grown with Czochralski method. It has good temperature stability and physical and mechanical properties. It is ideal for optical polarizing components because of its wide transparency range and large birefringence. It is an excellent synthetic substitute for Calcite (CaCO3) and Rutile (TiO2) crystals in many applications including fiber optic isolators and circulators, interleavers, beam displacers and other polarizing optics ( refer to Table 1).
LiNbO3 crystal combines low cost, good mechanical and physical properties as well as high optical homogeneity. Therefore, LiNbO3 wedges have been widely used in fiber isolators and circulators.
α-BBO (α-BaB2O4) is a negative uniaxial crystal which has large birefringence over a broad transparent range of 190nm to 3500nm. α-BBO is an excellent crystal especially in UV and high power applications. The physical, chemical, thermal and optical properties of α-BBO crystal are similar to those of β-BBO. However, the nonlinear optical properties of α-BBO crystal are nonexistent due to the centric symmetry with its crystal structure. α-BBO crystal is not recommended for NLO processes.