BBO3

BBO (β-barium borate, BaB₂O₄) is a nonlinear optical ceramic compound valued for its transparency across the ultraviolet to infrared spectrum and strong nonlinear optical properties. It is primarily used in frequency conversion applications—particularly harmonic generation and parametric down-conversion—in high-power laser systems where alternative nonlinear crystals cannot operate due to phase-matching requirements or thermal constraints. Engineers select BBO for demanding photonics applications where its wide transparency window, high damage threshold, and ability to achieve critical phase-matching angles outweigh its relative brittleness and cost compared to more conventional optical materials.