Patent ID: 6621623
Filing Date: 2003-09-16
Classification: H01S

Abstract:
An optical fiber amplifying apparatus for directly amplifying input signal lights, comprising:an optical fiber for amplifying input signal lights, and a temperature control means for controlling the temperature of the optical fiber, provided with: a signal light extracting means for extracting at least one signal light out of wavelength-multiplex signal lights supplied from said optical fiber, and a level detecting means for detecting the level(s) of the extracted signal light(s), wherein said temperature control means is provided with: a heating/cooling element for heating or cooling said optical fiber, and a temperature control circuit for controlling the heating/cooling element on the basis of the level(s) of the detected signal light(s), said signal light extracting means includes: a first optical branching device, arranged on the output side of said optical fiber, for branching said wavelength-multiplex signal lights which have been amplified, a second optical branching device for branching the branched wavelength-multiplex signal lights into a plurality of branched lights, and an optical filter, arranged on the output side of the second optical branching device, for extracting a signal light of a prescribed wavelength out of each branched light.