Abstract: In order to add a CDC function to a ROADM system currently incompatible with CDC, without requiring any service outage, an optical communication system of the present invention includes: an optical demultiplexing unit 1-1 and 1-2 which each demultiplexes a wavelength-multiplexed optical signal inputted thereto and an optical multiplexing unit 2-1 and 2-2 which each multiplexes together some of, specifically at least two or more of, the components of the wavelength-multiplexed optical signal having been demultiplexed by the optical demultiplexing unit 1-1 or 1-2; and an optical path selection unit 3 which selectively outputs either the optical signal multiplexed by the optical multiplexing unit 2-1 or that by the optical multiplexing unit 2-2, in a form of at least two or more output optical signals.

Abstract: An optical amplification control apparatus is provided with: a first branch unit for branching an optical signal to which an additional optical signal with a predetermined wavelength has been added in a self node or a nearest node; a first filter unit for extracting the additional optical signal from one optical signal into which the first branch unit has branched; an amplification unit for amplifying the other optical signal into which the first branch unit has branched; a second branch unit for branching the optical signal amplified by the amplification unit; a second filter unit for extracting the additional optical signal from one optical signal into which the second branch unit has branched; and a first control unit for performing automatic gain control of the amplification unit based on the additional optical signal extracted by the first filter unit, and the additional optical signal extracted by the second filter unit.

Abstract: In order to add a CDC function to a ROADM system currently incompatible with CDC, without requiring any service outage, an optical communication system of the present invention includes: an optical demultiplexing unit 1-1 and 1-2 which each demultiplexes a wavelength-multiplexed optical signal inputted thereto and an optical multiplexing unit 2-1 and 2-2 which each multiplexes together some of, specifically at least two or more of, the components of the wavelength-multiplexed optical signal having been demultiplexed by the optical demultiplexing unit 1-1 or 1-2; and an optical path selection unit 3 which selectively outputs either the optical signal multiplexed by the optical multiplexing unit 2-1 or that by the optical multiplexing unit 2-2, in a form of at least two or more output optical signals.

Abstract: An optical amplification control apparatus is provided with: a first branch unit for branching an optical signal to which an additional optical signal with a predetermined wavelength has been added in a self node or a nearest node; a first filter unit for extracting the additional optical signal from one optical signal into which the first branch unit has branched; an amplification unit for amplifying the other optical signal into which the first branch unit has branched; a second branch unit for branching the optical signal amplified by the amplification unit; a second filter unit for extracting the additional optical signal from one optical signal into which the second branch unit has branched; and a first control unit for performing automatic gain control of the amplification unit based on the additional optical signal extracted by the first filter unit, and the additional optical signal extracted by the second filter unit.