Supervisory signal optical bypass circuit, optical amplifying repeater and supervisory system

摘要

A supervisory signal light bypass circuit which has: a first 2x2 optical coupler provided on a first optical transmission line; a second 2x2 optical coupler provided on a second optical transmission line through which signal light flows in the direction opposite to the first optical transmission line; a third optical transmission line that connects to one output port of the first optical coupler and one output port of the second optical coupler: a first reflecting member that is provided at another output port of the first optical coupler and has a first reflection wavelength; and a second reflecting member that is provided at another output port of the second optical coupler and has a second reflection wavelength.