Optical amplification block, and optical amplification system using the same

An optical amplification block comprising:

• an optical amplification media for making an optical amplification;
• a first branching device to input signal lights and feedback branched lights and branch the input lights into first branched lights and second branched lights, unamplified, as monitor lights, in specified proportions, the first branching device inputting the first branched lights to the optical amplification media;
• and
• a second branching device to input the output of the optical amplification media and branch the input lights into third branched lights as optical amplified outputs and fourth branched lights as feedback branched lights, in a predetermined proportion.

An optical amplification block comprising:

• an optical amplification media for making an optical amplification;
• a first branching device to input signal lights and branch the signal lights into first branched lights and second branched lights, in a predetermined proportion, and input the first branched lights to the optical amplification media;
• and
• a second branching device to input the output of the optical amplification media and the second branched lights, and branches third branched lights as optical amplified output and fourth branched lights as monitor lights, wherein the monitor lights comprise an amount of the second branched lights greater than an amount of the output of the optical amplification media.