Optical branch insertion device and optical branch insertion method

Abstract

The present invention is to provide an optical add/drop multiplexing device capable of realizing a configuration in which many transponders can be connected at low cost. An optical add/drop multiplexing deviceA includes branch function unitstoconnected to each of WSSstoconnected to respective routesto D having a plurality of optical fibers and dropping optical signals having a plurality of wavelengths among the optical signals having the respective wavelengths transmitted by wavelength division multiplexing. The optical add/drop multiplexing device includes C-function unitstoconfigured to transmit the optical signals branched by the branch function unitstoto a plurality of transponders. The optical add/drop multiplexing device includes optical couplerstoeach connected between a set of K WSSsandeach having 1 input and M outputs and one of the branch function units, K being a number of 2 or more, the number of optical couplers being equal to or greater than a positive integer obtained by dividing a numerical value D(M−D) by K, the numerical value being obtained by multiplying the number (M−D) of optical signals dropped by each of the WSSsandby the number D of all of the WSSsto. The optical couplercouples optical signals of different wavelengths dropped by a set of WSSs into one optical signal and outputs the coupled optical signal to the branch function unit