High-efficiency electrically tunable phase diffraction grating based on a transparent lead magnesium niobate-lead titanite electro-optic ceramic.

An electrically tunable high-efficiency phase diffraction grating using the transparent lead magnesium niobate-lead titanite (PMNT) electro-optic ceramic is proposed. A photomask technique is used for fabricating the grating with the Ti/Pt/Au interdigital electrodes. With the variation of the equivalent phase face induced by the quadratic electro-optic effect of the PMNT ceramic, the diffraction patterns of the light beam will be changed in which the diffraction efficiency may be controlled by an applied DC voltage. When the applied voltages are 41, 80, and 139 V, the zero-order, first-order, or second-order diffraction lights will disappear in turn with about 100% diffraction efficiency. The proposed grating can be used as an electrically controlled switch in the laser beam modulation and scanning, especially for the application of the high-power laser systems.