Birefringence as a function of upper-cladding layers in polymeric arrayed waveguide gratings

摘要

We investigated on the variation of polarization-dependent wavelength shifts in birefringent-polymeric arrayed waveguide gratings (AWG) along the each step of forming a core layer and a multi-layered upper cladding in fabrication processes. We found that the polarization-dependent wavelength shift is a function of the number of sublayers with a positive offset value depending on the thickness of the first sublayer and a negative slope depending on the thickness of the additional sublayers, resulting in a polarization-insensitive AWG with proper values of the thickness and the number.