Polarization-independent wavelength filter based on dual asymmetric long-period gratings in channel waveguides

摘要

Channel waveguides with asymmetric long period gratings exhibiting coupling from the fundamental (symmetric) core mode to the first-order (antisymmetric) cladding mode were analyzed. Using this geometry, we show that it is possible to realize polarization-dependent and polarization-independent operations at desired wavelengths. We have chosen the device parameters to demonstrate its operation in the C+L band. Sensitivity of the coupling behavior to random variation in various parameters such as core and cladding dimensions, grating period, etc., has been analyzed. The proposed structure should be interesting from the point of view of realizing waveguide devices such as filters, polarizers, etc., based on waveguide gratings.