| 摘要 |
PURPOSE: To obtain inexpensive and also favorable optical quality by fixing two wave lengths to be below the limit wave length of a waveguide and using a single mode fiber welding coupler having different fibers as a multiplexer, a demultiplexer and an exchange change-over equipment. CONSTITUTION: Optical signals S1 and S2 irradiated from optical transmitters 99 and 100 to the waveguide 104 are provided with mutually different wave lengths λ1 , λ2 and transmitted by mutually different waveguide modes LP11 and LP01 . Then, the multiplexer 41 and the demultiplexer 51 or the exchange change-over equipment are respectively the single mode fiber welding couplers 21 and 31 and the couplers 21 and 31 are produced by the fibers 22, 23, 32 and 33 with difference in the diameters of a core and a clad. Thus, a superior optical information transmitting system for transmitting the two optical signals by uni-two way or simultaneous exchange is obtained. |
