OPTICAL MULTIPLEXER/DEMULTIPLEXER IMPROVED IN GROUP DELAY CHARACTERISTIC

摘要

PROBLEM TO BE SOLVED: To minimize a group delay dispersion without changing the multiplexing/demultiplexing characteristics of an optical multiplexer/ demultiplexer when the number of stages of a lattice filter is increased and when the number of combination stages is increased, in the highly functional optical multiplexer/demultiplexer of M-input and M-output using the lattice filter as an optical multiplexing/demultiplexing element of two-input and two- output.;SOLUTION: The values of circuit parameters of respective stage lattice filters are designed so that group delay dispersions of multistage connected lattice filters 111-113 equale in amplitude characteristic but different in phase characteristic have inverse characteristics in the forward stage and in the backward stage. Thus, group delay dispersion is negated, consequently, group delay dispersion corresponding to second order derivative to a phase frequency is improved without changing the multiplexing/demultiplexing characteristics of the optical multiplexer/demultiplexer, and group delay dispersion is minimized as the whole of multistage lattice filter.;COPYRIGHT: (C)2002,JPO