Optical amplification system, optical amplification apparatus and optical amplification method

An optical amplification device having a plurality of optical amplification media cascade-connected, the optical amplification device comprising:

• a band divider that divides an optical signal into optical signals of two different bands;
• a polarization demultiplexer that separates the divided optical signal into two polarization components orthogonal to each other;
• an excitation light multiplexer that multiplexes the optical signal separated by the polarization demultiplexer and an excitation light;
• a first amplification medium that generates an optical parametric amplification process and amplifies the optical signal;
• a second amplification medium that generates the optical parametric amplification process and amplifies the optical signal amplified by the first amplification medium;
• an excitation light separator that separates the optical signal amplified by the second amplification medium and the excitation light;
• a polarization combiner that combines the two separated polarization components;
• and
• a band demultiplexer that multiplexes the two divided bands,
• wherein the plurality of amplification media are cascade-connected such that an amplification medium having a lower saturation output power and a higher gain at the time of saturation output is arranged at a preceding stage.

An optical amplification method by an optical amplification system including a plurality of optical amplifiers cascade-connected such that an optical amplifier having a lower saturation output power and a higher gain at the time of saturation output is arranged at a preceding stage, the optical amplification method comprising:

• a band division step of causing the optical amplifier to divide an optical signal into optical signals of two different bands;
• a polarization demultiplexing step of causing the optical amplifier to separate the divided optical signal into two polarization components orthogonal to each other;
• an excitation light multiplexing step of causing the optical amplifier to multiplex the optical signal separated in the polarization demultiplexing step and an excitation light;
• an amplification step of causing the optical amplifier to generate an optical parametric amplification process and amplify the optical signal;
• an excitation light separation step of causing the optical amplifier to separate the optical signal amplified in the amplification step and the excitation light;
• a polarization combining step of causing the optical amplifier to combine the two separated polarization components;
• and
• a band multiplexing step of causing the optical amplifier to multiplex the two divided bands.

An optical amplification method by an optical amplification device having a plurality of optical amplification media cascade-connected such that an optical medium having a lower saturation output power and a higher gain at the time of saturation output is arranged at a preceding stage, the optical amplification method comprising:

• a band division step of dividing an optical signal into optical signals of two different bands;
• a polarization demultiplexing step of separating the divided optical signal into two polarization components orthogonal to each other;
• an excitation light multiplexing step of multiplexing the optical signal separated in the polarization demultiplexing step and an excitation light;
• a first amplification step of generating, by a first amplification medium, an optical parametric amplification process and amplifying the optical signal;
• a second amplification step of generating, by a second amplification medium, an optical parametric amplification process and amplifying the optical signal amplified in the first amplification step;
• an excitation light separation step of separating the optical signal amplified in the second amplification step and the excitation light;
• a polarization combining step of combining the two separated polarization components;
• and
• a band multiplexing step of multiplexing the two divided bands.