Large Electro‐Optic Coefficient in Single‐Domain PIN‐PMN‐PT Single Crystal

Due to the excellent shear‐mode piezoelectric properties, single‐domain tetragonal Pb(In1/2Nb1/2)O3‐Pb(Mg1/3Nb2/3)O3‐PbTiO3 (PIN‐PMN‐PT) crystals are believed to possess giant electro‐optic (EO) coefficients as well. However, the EO properties of single‐domain PIN‐PMN‐PT crystals have not been systematically studied because of the difficulties in the single‐domain sample preparation. Here, by this newly developed orthogonal poling method, single‐domain tetragonal PIN‐PMN‐39PT crystals are successfully obtained by poling the sample along the non‐spontaneous polarization direction at room temperature. Optical grade crystal with good transparency and high EO coefficient component γ51 (≈2800 pm V−1) is achieved. The orientation dependence of the EO coefficient is analyzed based on the measured full matrix of the EO coefficients. This work confirms the giant EO performance of domain‐engineered PIN‐PMN‐PT single crystals mainly comes from the contribution of EO coefficient component γ51 of single domain crystal other than the domain wall or domain switching related mechanisms. A new method for fabricating transparent single‐domain PIN‐PMN‐PT crystal with high longitudinal piezoelectric and EO coefficient is proposed. A giant EO coefficient (γ51 ≈ 2700 pm V−1) is achieved and the spatial distribution of the longitudinal EO coefficient is further analyzed. Based on that, an EO beam deflector with significantly reduced driving voltage is designed.