Optical wavelength multiplex transmission system using repeaters
AssigneeNEC Corporation
InventorSeiji Watanabe
Life of this patent
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Abstract
An optical wavelength multiplex transmission system including repeaters is disclosed, in which a deviation (Δ(S/N)) of S/N ratios of optical wavelength components of a multiplex optical signal at an optical receiver unit becomes zero. In this system, the optical receiver unit is provided with an optical S/N ratio equalizing filter having such a loss characteristics that the optical S/N ratios of respective optical wavelength components of an optical receiving signal at the optical receiver unit becomes substantially same.
Claims13
An optical wavelength multiplex transmission system using repeaters, comprising:
- an optical transmitter unit for transmitting an optical wavelength multiplex signal;
- an optical transmission line including a plurality of optical amplifiers;
- an optical receiver unit for receiving the optical wavelength multiplex signal;
- and
- an optical S/N ratio equalizing filter having such a loss characteristics that optical S/N ratios of optical wavelength components of an optical receiving signal at said optical receiver unit are made substantially same,
- wherein said optical S/N ratio equalizing filter has a loss characteristics having the deviation of optical output power level of −40% to −60% of the gain-deviation characteristics of said optical transmission line including the plurality of said optical amplifiers, for the optical wavelength multiplex signal.
An optical communication system having a transmitter, an optical transmission line including a plurality of optical repeaters and a receiver, said transmitter comprising:
- a first light source for outputting first light having a first wavelength;
- a second light source for outputting second light having a second wavelength which is different from the first wavelength;
- a multiplex unit coupled to said first and second light sources, for multiplexing the first and second lights to output an optical wavelength multiplex signal;
- and
- an equalizing filter coupled to said multiplex unit, for filtering the optical wavelength multiplex signal from said multiplex unit and transmitting a filtered multiplex signal to the receiver through the optical transmission line to equalize deviation between optical S/N ratios of the first and second wavelength of the filtered multiplex signal which is received by the receiver,
- wherein said equalizing filter has a loss characteristics having the deviation of optical output power level of −40% to −60% of the gain-deviation characteristics of said optical transmission line including the plurality of said optical amplifiers, for the optical wavelength multiplex signal from said multiplex unit.
Dependencies are inferred from the claim text.