Polarization insensitive single mode Al2O3 rib waveguide design for applications in active and passive optical waveguides

Abstract

Both passive and active, single mode, wavelength and polarization insensitive design of Al2O3 rib waveguides on SiO2 substrate is reported. Influence of the waveguide height, etch depth, waveguide width and operation wavelength to the mode number, mode size, birefringence and polarization sensitivity were analyzed with Beam Propagation Method. Design parameters for targeted properties are computed for waveguide widths ranging from 0 to 10 mu m, and for etch depth ranging from 0 to 0.5 mu m for fixed waveguide height of 0.5 mu m. A design window for a fixed width of 3.5 mu m and etch depths between 0.325 to 0.375 mu m is identified for single mode, wavelength and polarization insensitive operation of Al2O3 waveguides on thermal oxide. A novel rib TE mode selective filter design is also suggested as an output of the numerical simulations.