Analysis on the electric field distribution in a relaxor ferroelectric KTN crystal near field-induced phase transition using optical deflection measurements.

Spatially analyzing non-uniform distributions of electric phenomena such as electric field and permittivity in ferroelectric devices is very challenging. In this study, we apply an optical beam deflection method to map the non-uniform electric phenomena in relaxor ferroelectric potassium tantalate niobate (KTN) crystals. To adequately correlate the physical parameters and their spatial distributions in KTN crystals, a general model that describes the giant electro-optic response and associated beam deflection is derived. The proposed model is in good agreement with the experimental results and is envisioned to be useful for analyzing electric field-induced phenomena in non-linear dielectric materials and devices.