Synthesis of a multichannel lattice-form optical delay-line circuit with ring waveguides

This paper presents a one-input M -output (1 x M) circuit configuration and a synthesis algorithm for realizing an optical infinite impulse response (IIR) lattice filter having M -output channels (M > or =2) .The circuit configuration has a multilayer structure consisting of multiple Mach-Zehnder interferometers with delay time difference of Deltatau. It is a natural extension of the conventional two-port optical IIR lattice circuit (M =2) . Synthesis algorithm is derived to obtain all unknown circuit parameters. The proposed synthesis algorithm is based on factorizations of the paraunitary total transfer matrix. Simulation result demonstrates the effectiveness of the proposed multichannel IIR design scheme. The synthesis algorithm for M - channel IIR filter is considered lossless in this paper, which implies that the filter must be power complementary.