Optical amplifier having a variable attenuator controlled based on detected ASE

An optical amplification device, comprising:

• a first segment of active optical fiber having first and second end portions coupled to a first optical communication path, said first optical communication path carrying a plurality of optical signals, each at a respective one of a plurality of wavelengths;
• an optical attenuator having an input port coupled to said second end portion of said first segment of optical fiber, said optical attenuator having a control port that receives an attenuation control signal, and an output port, said input port of said optical attenuator receiving said plurality of optical signals, an attenuation of said optical attenuator being adjusted in accordance with said attenuation control signal;
• a second segment of active optical fiber having a first end portion coupled to said output port of said optical attenuator and a second end portion, said plurality of optical signals propagating through said optical attenuator and being supplied to said first end portion of said second segment of active optical fiber via said output port of said optical attenuator, said plurality of optical signals being output from said second segment of active optical fiber via said second end portion of said second segment of active optical fiber;
• an optical coupler having an input port coupled to said second end portion of said active optical fiber, and first and second output ports, said plurality of optical signals being output through said second port to a second optical communication path;
• and
• an amplified stimulated emission (ASE) sensing circuit coupled to said second output port of said optical coupler, said ASE sensing circuit separately detecting ASE light at first and second wavelengths, said ASE light being emitted from said first and second segments of active optical fibers, said ASE sensing circuit further being coupled to said control port of said optical attenuator and generating said attenuation control signal based on optical power levels of said ASE light at said first and second wavelengths.