Lateral Optical Confinement in GaAs - Ga0.7Al0.3 As Heterostructure Waveguides Fabricated by Liquid-Phase Epitaxy Over Preferentially Etched Channels

Abstract

Recently, we introduced a new technique of fabricating optical waveguides with lateral optical confinement by first preferentially etching the waveguide channels in silicon substrate, and then filling the grooves with organic films by solution-deposition technique after a layer of SiO2 film was thermally grown as the optical insulating layer.1 We have extended the same concept of waveguide-formation to GaAs - Ga1-xAlxAs system by liquid-phase epitaxial technique.2 In this case, the waveguide channels were preferentially etched into the GaAs substrates, and then a layer of Ga0.7Al0.3As was grown on top of it followed by a second layer of GaAs. The GaAs layer serves as the light-guiding film, while the Ga0.7Al0.3As layer serves as the optical insulating layer.