Patent ID: 7031049
Filing Date: 2006-04-18
Classification: H01S

Abstract:
1. A loss point detecting method for determining whether or not a loss point occurs in an optical transmission path, in a distributed Raman amplifier which amplifies a signal light using the optical transmission path as an amplifying medium, by applying an excitation light to the optical transmission path in a first direction opposite to a second direction in which the signal light is transmitted through the optical transmission path, comprising: monitoring power of scattered light separating from the optical transmission path; separating part of the excitation light and monitoring power of the separated part of the excitation light; separating a reflected light which passes in the second direction, opposite to the first direction in which the excitation light passes through the optical transmission path, and monitoring power of the separated, reflected light; and determining, when the monitored power of the separated part of the excitation light reaches a predetermined determination value, whether or not a loss point occurs, based on a ratio between the monitored power of the scattered light and the monitored power of the separated, reflected light.