Electro-Optic Lead Lanthanum Zirconate Titanate PLZT

Electro-Optic Lead Lanthanum Zirconate Titanate (PLZT) 

The fabrication of PLZT is achieved in four general ways (i) hot pressing at 1000-1300°C and 20-60MPa (ii) pressureless sintering in a PbO atmosphere to account for evaporation losses of lead (iii) hot isostatic pressing and (iv) multistage sintering. 

The working principle of devices based on the nonlinear optical properties of PLZT lays in the change of birefringence in response to an external electric field. By modification of the optical indicatrix (i.e., the indices of refraction) the optical path lengths will be altered, such that the electronically triggered phase modulation of light is possible. As this phase modulation is different for the two waves 

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Lead lanthanum zirconate titanates (PLZT) containing 3-12 mol. % La and 5-30 mol. % Ti form a class of ceramics with important dielectric, piezoelectric and electro-optic properties. They may contain vacancies on B as well as A sites and have a remarkable facility for changing their polar states under the influence of applied fields. 

Transparent ferroelectric single crystals are traditionally used for electro-optic applications. Since the optical transparency was first discovered in lead-lanthanum-zirconate-titanate (PLZT), ferroelectric ceramics have been investigated in great depth such that, today, their characteristics allow them to compete with single crystals for certain electro-optic applications. The electro-optic properties of PLZT compositions are intimately related to their ferroelectric properties. Variations in ferroelectric polarization with an electric field, such as in a hysteresis loop, also affect the optical properties of the material. 

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