Optical amplifying apparatus for amplifying wide-wavelength-band light, optical sending apparatus, optical transmission system, and optical amplifying method

An optical sending apparatus comprising:

• at least two mutually exclusive wavelength bands, each having at least two channels;
• a plurality of optical sending means provided for the respective wavelength bands, and for generating WDM optical signals in the respective wavelength bands, wavelengths of the respective wavelength bands having approximately equal channel powers;
• a plurality of optical adjusting means connected to said respective optical sending means, for adjusting optical powers of light beams;
• wavelength-multiplexing means for wavelength-multiplexing outputs of said respective optical adjusting means for the respective wavelength bands;
• and
• controlling means for performing control so that an output of optical adjusting means for adjusting average optical power per single wavelength channel of shorter-wavelength-band light among said plurality of optical adjusting means becomes larger than an output of optical adjusting means for adjusting average optical power per single wavelength channel of longer-wavelength-band light among said plurality of optical adjusting means, and approximate channel powers of the shorter wavelength band light is greater than approximate channel powers of the longer wavelength band light.

An optical transmission system comprising:

• an optical sending apparatus generating an optical signal of a plurality of wavelength bands;
• an optical transmission line transmitting the generated said optical signal;
• an optical receiving apparatus receiving and processing said optical signal transmitted through said optical transmission line;
• and
• at least one optical amplifying apparatus provided on the optical transmission line, comprising:
• wavelength-demultiplexing means for wavelength-demultiplexing said optical signal on a wavelength band basis;
• at least two mutually exclusive wavelength bands, each having at least two channels;
• a plurality of optical adjusting means for adjusting optical powers of each said optical signal in the respective wavelength bands, that are output from said wavelength-demultiplexing means, and wavelengths of the respective wavelength bands having approximately equal channel powers;
• wavelength-multiplexing means for wavelength-multiplexing outputs of said respective optical adjusting means;
• and
• controlling means for performing control so that an output of optical adjusting means for adjusting average optical power per single wavelength channel of shorter-wavelength-band light among said plurality of optical adjusting means becomes larger than an output of optical adjusting means for adjusting average optical power per single wavelength channel of longer-wavelength-band light among said plurality of optical adjusting means, and approximate channel powers of the shorter wavelength band light is greater than approximate channel powers of the longer wavelength band light.

A method of amplifying light comprising:

• providing at least two mutually exclusive wavelength bands, each having at least two channels, and wavelengths of the respective wavelength bands having approximately equal channel powers;
• amplifying light in a longer-wavelength band among a plurality of wavelength bands;
• amplifying light in a shorter-wavelength band among said plurality of wavelength bands to have average optical power per single wavelength channel that is larger than average optical power per single wavelength channel of the amplified light in the longer-wavelength band, wherein approximate channel powers of the shorter wavelength band is greater than approximate channel powers of the longer wavelength band;
• and
• wavelength-multiplexing light beams of the plurality of wavelength bands.

A method of amplifying light comprising:

• generating a plurality of optical signals having different optical powers;
• generating a plurality of WDM optical signals by wavelength-multiplexing said plurality of optical signals on a wavelength band basis;
• providing at least two mutually exclusive wavelength bands, each having at least two channels, and wavelengths of the respective wavelength bands having approximately equal channel powers;
• amplifying a WDM optical signal in a longer-wavelength band among the plurality of WDM optical signals;
• controlling an optical gain of respective said wavelength bands to have average optical power per single wavelength channel that is larger than average optical power per single wavelength channel of the amplified WDM optical signal in said longer-wavelength band, wherein approximate channel powers of the respective wavelength bands are greater than approximate channel powers of said longer wavelength band;
• and
• wavelength-multiplexing said plurality of WDM optical signals.

A method of inputting light comprising:

• providing at least two mutually exclusive wavelength bands, each having at least two channels, and wavelengths of the respective wavelength bands having approximately equal channel powers;
• making average optical power per single wavelength channel of a WDM optical signal in a shorter-wavelength band larger than average optical power per single wavelength channel of a WDM optical signal in a longer-wavelength band among a plurality of WDM optical signals in respective wavelength bands, wherein approximate channel powers of the shorter wavelength band is greater than approximate channel powers of the longer wavelength band;
• and
• inputting said plurality of WDM optical signals in the respective wavelength bands to an optical transmission line.

An optical amplifying apparatus comprising:

• a wavelength demultiplexing unit to wavelength demultiplex optical signal light into light beams of respective wavelength bands;
• at least two mutually exclusive wavelength bands, each having at least two channels;
• a plurality of optical adjusting units provided for the respective wavelength bands, to individually adjust average optical power per single wavelength channel of the light beams, and wavelengths of the respective wavelength bands having approximate equal channel powers;
• a wavelength multiplexing unit to wavelength multiplex outputs of the respective optical adjusting units;
• and
• a control unit to perform control of the optical adjusting units so that an output of a respective optical adjusting unit for adjusting average optical power per single wavelength channel of shorter-wavelength-band light among the plurality of optical adjusting units becomes larger than an output of a respective optical adjusting unit for adjusting average optical power per single wavelength channel of longer-wavelength-band light among the plurality of optical adjusting units, and approximate channel powers of the shorter wavelength band light is greater than approximate channel powers of the longer wavelength band light.

An optical transmission system comprising:

• an optical sending device to generate optical signal light of a plurality of wavelength bands;
• an optical transmission line to transmit the optical signal light;
• an optical receiving device to receive and process the optical signal light transmitted through the optical transmission line;
• and
• at least one optical amplifying device provided on the optical transmission line, comprising:
• a wavelength demultiplexing unit to wavelength demultiplex the optical signal light into light beams of the respective wavelength bands;
• at least two mutually exclusive wavelength bands, each having at least two channels;
• a plurality of optical adjusting units provided for the respective wavelength bands, to individually adjust optical powers of the light beams, and wavelengths of the respective wavelength bands having approximate equal channel powers;
• a wavelength multiplexing unit to wavelength multiplex outputs of the respective optical adjusting units;
• and
• a control unit to perform control of the optical adjusting units so that an output of a respective optical adjusting unit for adjusting average optical power per single wavelength channel of shorter-wavelength-band light among the plurality of optical adjusting units becomes larger than an output of a respective optical adjusting unit for adjusting average optical power per single wavelength channel of longer-wavelength-band light among the plurality of optical adjusting units, and approximate channel powers of the shorter wavelength band light is greater than approximate channel powers of the longer wavelength band light.