Polarization independent wavelength tunable filter based on birefringence compensation

摘要

A polarization independent wavelength tunable filter in the form of a dual-waveguide directional coupler. The conditions necessary to achieve coupling of a selected wavelength including both TE and TM polarization modes from one waveguide to a second waveguide in close proximity are achieved through a combination of geometrical and compositional tailoring of the waveguides and birefringence compensation in the waveguide and coupling layer.