Crystal are most applied for laser application.
 
the categories of optical mirrors including
 Ÿ Laser Crystals and Rods: YAG crystal, Nd: YVO4 Crystal
 Ÿ Nonlinear Crystals: BBO, KTP, LiNbO3, LBO. KDP&DKDP
 Ÿ Birefringent Crystals: YVO4, a-BBO, Calcite.