A polarization-independent distributed Bragg reflector based on phase-shifted grating structures

A polarization-independent narrow-band Bragg reflector based on a novel phase-shifted grating structure is proposed and analyzed. Operation and design principles for the proposed grating structure as an polarization-independent optical filter are described. Robustness of the polarization-independent filter against modal birefringence and polarization effects in grating couplings and modal losses are examined and verified. Tunability of the polarization-independent filter is also studied and demonstrated.