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US 7,924,497 B2Granted
System and method for gain equalization and optical communication system incorporating the same
AssigneeTyco Electronics Subsea Communications LLC
InventorsMorten Nissov, Alexei N. Pilipetskii, Alan J. Lucero
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Abstract
An optical amplifier including gain equalization and system incorporating the same. The amplifier includes a Raman portion and an EDFA portion with a gain flattening filter coupled between the Raman portion and the EDFA.
Claims19
An optical communication system comprising:
- a transmitter configured to transmit an aggregate optical signal comprising plurality of optical signals at different associated wavelengths in a signal bandwidth;
- a receiver configured to receive said aggregate optical signal and detect data modulated on said plurality of optical signals;
- and
- a transmission path extending between said transmitter and said receiver, said transmission path comprising,
- at least first and second amplifiers separated by a transmission span of at least 120 km in length, at least the first amplifier being a hybrid Raman/EDFA amplifier comprising:
- a Raman portion comprising a transmission path segment configured to be pumped by at least one Raman pump to impart Raman gain to at least a portion of said signal bandwidth,
- an EDFA portion comprising at least one erbium-doped fiber configured to be pumped by at least one EDFA pump to impart EDFA gain to at least a portion of said signal bandwidth, and
- a gain flattening filter coupled between said Raman portion and said EDFA portion of said hybrid Raman/EDFA with no gain flattening filter coupled to an output of said EDFA portion,
- wherein said at least one Raman pump and said at least one EDFA pump are configured to pump said transmission path segment and said erbium-doped fiber segment, respectively, to achieve an amplifier gain with amplified spontaneous emission (ASE) noise generated by said Raman portion exceeding ASE noise generated by said EDFA portion.
6 more elements
An optical communication system comprising:
- a transmitter configured to transmit an aggregate optical signal comprising plurality of optical signals at different associated wavelengths in a signal bandwidth;
- a receiver configured to receive said aggregate optical signal and detect data modulated on said plurality of optical signals;
- and
- a transmission path extending between said transmitter and said receiver for length at least 600 km and spanning a body of water, said transmission path comprising,
- a plurality of hybrid Raman/EDFA amplifiers, successive ones of said amplifiers being separated by a transmission span of at least 120 km in length, each of said amplifiers comprising
- a Raman portion comprising a transmission path segment configured to be pumped by at least one Raman pump to impart Raman gain to at least a portion of said signal bandwidth,
- an EDFA portion comprising at least one erbium-doped fiber configured to be pumped by at least one EDFA pump at a pump power of less than about 400 mW to impart EDFA gain to at least a portion of said signal bandwidth, and
- a gain flattening filter coupled between said Raman portion and said EDFA portion of said hybrid Raman/EDFA with no gain flattening filter coupled to an output of said EDFA portion, and
- wherein amplified spontaneous emission (ASE) noise generated by said Raman portion exceeds ASE noise generated by said EDFA portion.
6 more elements
A method of amplifying an optical signal to launch the signal on a transmission span of at least 120 km using a hybrid Raman/EDFA amplifier including a Raman gain portion having an output coupled to an input of an EDFA gain portion, said method comprising
- flattening amplifier gain only between the Raman gain portion and the EDFA gain portion of said hybrid Raman/EDFA;
- pumping said EDFA portion at a pump power less than about 400 mW;
- and
- pumping said Raman portion to achieve an amplifier gain with amplified spontaneous emission (ASE) noise generated by said Raman portion exceeding ASE noise generated by said EDFA portion.
1 more element
Dependencies are inferred from the claim text.