Patent ID: 6724954
Filing Date: 2004-04-20
Classification: G02B

Abstract:
An optical multiplexer/demultiplexer, comprising:(a) first, second and third optical multiplexer/demultiplexer circuits that include: first, second, third and fourth ports; a first optical path that has said first and third ports as terminals; a second optical path that has said first and fourth ports as terminals; a third optical path that has said second and fourth ports as terminals and that has the same wavelength loss characteristics as said first optical path and the same absolute-value wavelength dispersion characteristics as said first optical path, the sign of the wavelength dispersion characteristics being opposite to each other between the first and third optical paths; and a fourth optical path that has said second and third ports as terminals and that has the same wavelength loss characteristics as said second optical path and the same absolute-value wavelength dispersion characteristics as said second optical path, the sign of the wavelength dispersion characteristics being opposite to each other between the second and fourth optical paths; wherein Mach-Zehnder interference circuits are connected in series and in multistage and at least of one pair of said first, second and third optical multiplexer/demultiplexer circuits are placed in mirror image relation; (b) an optical path that lies connecting said first optical path of the said first optical multiplexer/demultiplexer circuit and said third optical path of the said second optical multiplexer/demultiplexer circuit such that a wavelength dispersion generated in the first optical path of said first optical multiplexer/demultiplexer circuit is compensated by said second optical multiplexer/demultiplexer circuit; and (c) an optical path that lies connecting said second optical path of the said first optical multiplexer/demultiplexer circuit and said fourth optical path of the said third optical multiplexer/demultiplexer circuit such that a wavelength dispersion generated in the second optical path of said first optical multiplexer/demultiplexer circuit is compensated by said third optical multiplexer/demultiplexer circuit.