SBN-75 (Strontium-Barium Niobate, SrxBa(1-x)Nb2O6) is a mixed oxide crystal material that combines strontium and barium niobates in a solid solution. It is a highly efficient nonlinear optical crystal material, characterized by large nonlinear coefficients, broad transmission range and high damage threshold. It is widely used as a frequency doubler in various solid-state and fiber laser systems. The value of x in the formula SrxBa(1-x)Nb2O6 refers to the proportion of strontium and barium present in the crystal, and the number 75 refers to the mole fraction of barium. The specific properties of SBN-75 crystals can be tailored by varying the composition of strontium and barium to meet the requirements of different applications.