Tuning the modal birefringence in waveguide devices

摘要

Recent results for tuning the effective index birefringence are presented. In the firstrnexample, the birefringence of micron-scale silicon-on-insulator (SOI) ridge waveguides isrncontrolled using the stress induced by a SiO2 cladding. In the second example, a high index caprnlayer is used to shift the difference between TE and TM mode effective index in selected areas of arnsilica or SOI slab waveguide. Both approaches are demonstrated experimentally as practicalrnmethods to eliminate the polarization sensitivity of silica and SOI waveguide spectrometers, whilernincurring negligible extra waveguide losses.