Optical transmission system having an optical add-drop multiplexer and optical add-drop

摘要

PROBLEM TO BE SOLVED: To precisely branch and insert signal light with simple constitution and at low loss by providing a light branching/inserting device for the branch point of an optical transmission line with which plural terminal stations are connected to each other and outputting the signal light of a desired wavelength, which is inputted from the terminal station, to the desired terminal station. ;SOLUTION: A first branching part 11-1 outputs the signal light of the desired wavelength among signal light inputted from an incoming input-side optical fiber 14-1 to a first insertion part 11-2 through an optical fiber 14-3 and the signal light of the other wavelength is outputted to a third insertion part 13-2 through an optical fiber 14-4. A first insertion part 11-2 synthesizes signal light inputted from a branching input-side optical fiber 16-1 through a third branching part 13-1 and an optical fiber 14-5 with signal light inputted from the first branching part 11-1 and outputs them to an up output-side optical fiber 14-2. Thus, first - third branching parts 11-1 to 13-1 and the first - third insertion parts 11-2 to 13-2 are provided to branch or insert the signal light of the plural wavelengths in accordance with the wavelength.;COPYRIGHT: (C)1998,JPO