ARROW Waveguides Fabricated with SiO[sub x]N[sub y] and a-SiC:H Films

Abstract

The simulation, fabrication and characterization of Anti‐Resonant Reflecting Optical Waveguides (ARROW) using dielectric films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique at low temperatures (∼300 °C) are presented in this work. For numerical simulations, home‐made routines based in two computational methods were developed: the Transfer Matrix Method (TMM) used for the determination of the optimum thickness values of the Fabry‐Perot layers, and the Finite Difference Method for 2D design and determination of the maximum width which allows single‐mode operation. Also, since the simulations showed that the utilization of high refractive index differences between the core and the first ARROW layer produce lower optical attenuations, amorphous hydrogenated silicon carbide (a‐SiC:H) films were used as first cladding layer. These films present refractive index values greater than Si3N4 films (material commonly used as first ARROW layer). Furthermore, silicon oxynitride (SiOxNy) films, also deposited by PECVD technique, were used as core and second cladding layers and the definition of the lateral dimensions were achieved using Reactive Ion Etching (RIE) technique. Finally, optical waveguides using titanium oxide (TiO2) as the first ARROW layer were also fabricated, characterized and compared with the optical results of the silicon carbide ARROW waveguide and with the theoretical results.