System for detecting faults in an optical star coupler

摘要

A system of detecting an occurrence of a problem or fault in an optical communication line having a plurality of nodes with a sending port and a receiving port, a plurality of 2-input and 2-output couplers and fibers connecting the nodes and the couplers for distributing any signal issued from a node to all the nodes. The coupler has an intersecting allocation between two inputs and two outputs. The intersection in the coupler makes the recurring signal pass only through a series of evanescent linkages of the couplers to the receiving port of the same node. When a problem arises, the evanescent linkage is more likely to be broken down than the direct linkage and the node notices the problem by the extinction of the recurring signal.