Method of polarisation compensation in grating- and phasar-based devices by using over-layer deposited on the compensating region to modify local slab waveguide birefringence

摘要

The method consists of creating a compensating region within the slab waveguide region, with effective TE and TM mode refractive indices of the compensating region higher than those of the original slab waveguide. Such change in refractive indices is achieved by deposition of an over-layer on the compensating region.