PURPOSE: To realize the miniaturization and to reduce the cost by collecting input and output terminals to one side, and to execute a 4-wave division multiplex transmission from two pieces of optical direction couplers and two pieces of optical waveguides whose optical path length is different from each other. ;CONSTITUTION: By folding back optical waveguides 31, 41, 32 and 42, and output terminal is set to the same side as an input terminal. When wavelength multiplex optical signals 1, 2, 3, and 4 are inputted to the input terminal of an optical demultiplexer 13, 1 and 2 pass through the optical demultiplexer 13, and 3 and 4 are demultiplexed by the optical demultiplexer 13. 1 and 2 are allowed to branch by an optical directional coupler 11, one of them is propagated through the inside of the optical waveguide 31 of length L, and made incident on a second optical directional coupler 21. The other is propagated through the inside of the optical waveguide 41 of length L+L1, and made incident on a second optical directional coupler 21. They are multiplexed by the optional directional coupler 21, and 1 and 2 are demultiplexed. In the same way, 3 and 4 are demultiplexed to 3 and 4 by a Mach-Zehnder type optical multiplexer/demultiplexer 142 consisting of an optical directional coupler 12, the optical waveguides 32, 42, and an optical directional coupler 22. 1 and 4 are set as a 1.3m band and a 1.5m band.;COPYRIGHT: (C)1994,JPO&Japio
展开▼
