Passband broadening of integrated arrayed waveguidefiltersusing multimode interference couplers

Abstract

Passband broadening of arrayed waveguide filters that are compatible with singlemode fibre is demonstrated using an integrated multimode interference coupler at the entrance to the star coupler. An 8 × 1.6 nm filter is realised for the 1.55 µm band with 0.75 nm-wide –1 dB passbands and –20 dB rejection at >1.7 nm bandwidth.