Huge birefringence in selectively oxidized GaAs/AlAs optical waveguides

Abstract

Selective wet oxidation of AlAs was used to obtain huge birefringence in GaAs/AlAs optical waveguides. A single polarization waveguide was obtained by oxidizing an AlAs layer buried in a GaAs guiding layer. The TM mode is below cutoff due to the high index contrast between the layers. Applications to phase matching in nonlinear optical conversion are envisaged.