Linear electrooptic properties of Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals at compositions near the morphotropic phase boundary

The linear electrooptic coefficients of Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) single crystals in the rhombohedral and tetragonal phases were characterized at a wavelength of 632.8 nm. Large electrooptic responses were observed. The tetragonal 0.62PMN-0.38PT single crystals poled along the (001) direction (the spontaneous polarization direction) show r(33) = 70 pm/ V, r(13) = 25 pm/V, and r(51) = 558 pm/V. In addition, r33 and r13 of crystals of this composition show a slight increase with temperature, which originates from the temperature dependence of polarization and dielectric constant. The rhombohedral 0.67PMN-0.33PT single crystals poled along the <111> direction have r(33) = 107 pm/V, r(13) similar to 0, and r(51) = 1050 pm/ V.