PLZT ceramics electro-optic effects

Ceramic PLZT has a number of structures, depending upon composition, and can show both the Pockels (linear) electro-optic effect in the ferroelectric rhombohedral and tetragonal phases and the Kerr (quadratic) effect in the cubic paraelectric state. Because of the ceramic nature of the material, the non-cubic phases show no birefringence in the as-prepared state and must be poled to become useful electro-optically (Section 6.4.1). PMN-PT and PZN-PT are relaxor ferroelectrics. These have an isotropic structure in the absence of an electric field, but this is easily altered in an applied electric field to give a birefringent electro-optic material. All of these phases, with optimised compositions, have much higher electro-optic coefficients than LiNb03 and are actively studied for device application. 

As mentioned above, electro-optical ceramics such as PLZT have composition regions that exhibit (a) memory effects (b) primary electro-optical effects and... 

Figure 11 shows the change in the refractive indices AWj and Ang as a function of an applied dc electric field for a PLZT (9.5/65/35) ceramic. The dc field was cycled from 0 to +1.1 MV.m+ down to -1.1 MV.m i, and back up to 0. Awj remained near zero while Afig decreased quadratically with the dc field, due to the electro-optic Kerr effect, until a minimum of -... 

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