Optical Properties of Ca0.25Ba0.75Nb2O6 Thin Films Prepared by Spinning Coating

Ca0.25Ba0.75Nb2O6 (CBN25) thin film was prepared on quartz substrate by spinning coating and the optical properties were investigated by a Hitachi U-3410 spectrophotometer and a Metricon 2010 prism coupler. The optical band gap, thickness and refractive index at 632.8 nm of the CBN25 thin film were determined to be 3.65 eV, 529 nm and 2.2258, respectively. The dispersion of the refractive index fitted to Sellmeier relation well and optical waves could be guided into the thin film, which implied that CBN25 thin films were promising for integrated optics and optically active devices.