Patent ID: 6738132
Filing Date: 2004-05-18
Classification: G01M,H01S,H04B

Abstract:
A Raman amplifying apparatus, comprising:a first outputting means for outputting an excitation light to an optical fiber; a measuring means for measuring a Raman gain using return light attributable to back scattering in a signal band outputted from the optical fiber; a controlling means for controlling a power of the excitation light based on a result of the measuring means; a test light for providing a test light of a wavelength different from the excitation light; and a wavelength division multiplex coupler arranged to multiplex the excitation light and the test light wavelength going to the optical fiber and to demultiplex the return light coming from the optical fiber, wherein, the first outputting means comprises an excitation light source for providing the excitation light to the coupler; the measuring means comprises wavelength filter connected to the coupler, an optical attenuator connected to the filter, and an optical time domain reflectometry device connected to the attenuator, and the controlling means receives a signal from the optical time domain reflectometry device and is connected to the excitation light source for controlling the power of the excitation light.