Investigation of relaxor PLZT thin films as resonant optical waveguides and the temperature dependence of their refractive index

Abstract

Relaxor lead lanthanum zirconate titanate (PLZT) thin films, with compositions of (7/65/35), (8/65/35), and (9/65/35), have been investigated as optical waveguides. Resonant structures were observed in the reflected light beam that passes through these thin films after coupling with a laser-inscribed azo polymer surface relief diffraction grating. The temperature was then varied on the PLZT thin films between -20 and 70 degrees C, and a shift in the above resonance peaks was observed that is due to a change in the refractive index of the samples. The temperature dependence of the refractive index of the tested PLZT thin films was subsequently plotted and was found to decrease linearly with an increase in temperature at different rates for all the thin-film compositions tested.