| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical amplifier that does not deteriorate a noise figure even when a higher level optical signal is received. SOLUTION: An optical signal 102 subjected to wavelength multiplex received at an input terminal 101 is amplified by a pre-stage optical amplifier section 108 and then amplified by a post-stage optical amplifier section 113 and the amplified signal is outputted from an output terminal 115. A 1st control section (ATC) 121 conducts temperature control so as to control a temperature of a pre-stage exciting light source 106 that supplies a stimulated light 107 to the pre-stage optical amplifier section 108 to be a desired constant temperature. Furthermore, a 2nd control section (APC) 122 controls the power of the stimulated light 107 to be constant. Moreover, a 3rd control section (ALC) 123 receives a reference signal consisting of specific wavelength components of the optical signal amplified by the post stage optical amplifier section 113 and controls the stimulated light 111 to be fed to the post stage optical amplifier section 113 so as to the level of the reference signal to be constant. |
