OPTICAL MULTIPLEXER/DEMULTIPLEXER

摘要

PROBLEM TO BE SOLVED: To provide an optical multiplexer/demultiplexer which has a short tip length and a low loss at low cost. SOLUTION: In an optical multiplexer/demultiplexer in which a plurality of stages of optical multiplexing and demultiplexing circuits 8 (8A through 8G) having a Mach-Zehnder optical interferometer type waveguide composition are connected, the average wavelength of cross propagation wavelengths is longer than the average wavelength of through propagation wavelengths at respective stages of the optical multiplexing and demultiplexing circuits 8 (8A through 8G), in which the coupling efficiency of a first and a second directional coupling parts 1 and 2 with respect to the average wavelength of the cross propagation wavelengths is 50%.