alpha-BBO, α-BBO, a-BBO Plates and Blocks

High temperature phase BBO (alpha-BBO, a-BBO) is a negative uniaxial crystal with a large birefringence over the broad transparent range from 189 nm to 3500 nm. The physical, chemical, thermal, and optical properties of alpha-BBO crystal are similar to those of the low temperature phase beta-BBO crystal. However, there is no second order nonlinear effect in alpha-BBO crystal due to the centrosymmetry in its crystal structure and thus it has no use for second order nonlinear optical processes. Instead, alpha-BBO is widely used for fabrication of polarizers, polarizing beam displacers, phase retarders, birefringent plates, and time delay compensators especially those for UV and high power lasers.