Studies on key nano-fabrication processes for GaAs-based air-bridge-type two-dimensional photonic-crystal slab waveguides

Abstract

We report successful studies on improved key nano-fabrication processes for AlGaAs-based air-bridge-type two-dimensional photonic-crystal (2DPC) slab waveguides. The first topic is proximity-effect correction in electron beam lithography for the definition of a uniform and precise periodic/non-periodic 2DPC waveguide pattern. The second topic is optimization of the selective wet-etching condition in an air-bridge fabrication process. The resultant nano-fabrication processes have been proved to be quite effective for the realization of 2DPC slab waveguides such as modified and topology-optimized bend waveguides having broad-band and high-transmittance spectra in excellent agreement with the calculated ones.