Analysis and design of active optical filter structures with two-port couplers

A signal processing approach to modeling, analyzing, and synthesizing a particular integrated photonic architecture of optical filters with tunable gains is presented. This particular architecture has two-port couplers and current-controlled semiconductor optical amplifiers (SOAs) fabricated on the same substrate. The device architecture forms a new lattice filter structure. Layer-peeling-type algorithms are developed for the analysis and synthesis of the device. The role of the adjustable gains in a lossless or lossy device is considered, and a novel stability algorithm for the filter structure is presented.