TEST SYSTEM OF BEAM PATH FOR SEARCHING TROUBLE IN BEAM PATH FROM USER OPTICAL TERMINAL SIDE

摘要

A trouble searching system of a beam path searches a trouble in the beam path connected with an optical fiber, performing data transmission between a center-station-side transmitter and a user optical terminal through an optical branch unit (PON: Passive Optical Network). An optical pulse tester (Optical Time Domain Reflectometer: OTDR) feeds a test light to the optical fiber and tests the optical fiber based on a backscattering light or a return light from that optical fiber. A connecting part removes the terminal part of the beam path in the user optical terminal from the inside thereof and connects the OTDR to the terminal part of the beam path. An incident section feeds at least one of a test light having a wavelength different from that of a light being used for data transmission on the beam path and a test light having a specified peak level or lower to the terminal part of the beam path from the OTDR. A searching section searches a trouble in the beam path from the user optical terminal side by detecting a backscattering light or a return light from the beam path being obtained based on incidence of the test light using the OTDR.