The use of lithium niobate single crystal .
Lithium niobate crystal is one of the most widely used new inorganic materials at present. It is a good piezoelectric transducer material, ferroelectric material, electro-optic material, nonlinear optical material and surface wave matrix material. Lithium niobate plays an optical modulation role in optical communication as an electro-optic material. Electrooptic effect is the effect of the change of the refractive index of the crystal when the electric field is applied to the crystal. Some crystals due to the spontaneous polarization inherent electric dipole moment, when the applied electric field on the crystal orientation, the electric dipole moments in the crystal orientation in a consistent or an advantage orientation, therefore, must change the refractive index of the crystal, the crystal light external electric field change rate. In optical communication, an electric - light modulator is made of the principle that the refractive index of the crystal is changed by an electric field. The electro-optic crystal is located between the polarizer and the polarizer. When the electric field is not applied, the polarizing mirror and the polarizer are perpendicular to each other. The natural light can not be passed through the polarizing mirror after the polarizing mirror. When the electric field is applied, the light rate body changes, and the light can pass through the bias mirror. The intensity of the light of the polarizer is controlled by the voltage applied to the crystal, so as to achieve the purpose of modulating the intensity of the light by controlling the voltage.