Ytterbium doped ZnO nanolaminated planar waveguide for ring resonator applications

Abstract In the present paper, optical and structural properties of Yb doped ZnO (YZO) are studied for different Yb molar concentrations. The YZO thin films are deposited over the silicon substrate via the sol-gel spin coating method. The range of Yb doping content (concentration) is 0 mol% to 1.5 mol% in ZnO. The morphological variations of the deposited thin film are studied using XRD, FE-SEM, atomic force microscopy, and Ellipsometer. The obtained results indicate that the YZO thin film possesses a single crystalline structure with (1 0 0) as the preferential orientation. All samples have a smooth, dense structure and are free of pinholes. A detailed optical result showed a favorable behavior of YZO thin film for integrated photonic devices. Hence, an optical ring resonator is simulated using MODE and FDTD tool of Lumerical to validate the experimental results. The eigen mode solver is incorporated in MODE (wavelength ranging from 300 to 800 nm) to compute refractive index, propagation constant, group velocity, losses, dispersion and transmission intensity. Furthermore, quality factor, free spectral range and fullwidth at half-maximum of the ring resonator are evaluated using FDTD.