Large Electro-optic Effect In Single-crystal Pb(zr,ti)o_3 (001) Measured By Spectroscopic Ellipsometry

摘要

Using spectroscopic ellipsometry electro-optic effect was studied in lead zirconate titanate (PZT) thin films grown epitaxially on Nb-doped SrTiO_3(001) substrates by RF magnetron sputtering. A uniaxial multilayer model analysis was applied to extract the linear and quadratic electro-optic coefficients from the shifts in the ordinary and extraordinary refractive indices with electric field applied along the (001) direction. The effective linear and quadratic coefficients were measured as -134.6 × 10~(-12) m/V and 8.5 × 10~(-18) m~2/V~2, respectively, at a wavelength of 632.8 nm, while the individual linear electro-optic coefficients r_(33) and r_(13) were -157.1 and 22 pm/V, respectively. The existence of the linear electro-optic effect in unpoled PZT films was attributed to the presence of a built-in polarization and simultaneous poling during measurements.