Multiband amplifier based on discrete SOA-Raman amplifiers
AssigneeAT&T Corp.
InventorsPatrick Iannone, Kenneth Reichmann, Xiang Zhou
Life of this patent
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Abstract
Several discrete hybrid amplifiers are used in parallel for amplifying an optical signal in an optical fiber system. An optical signal is first split into two or more separate signals each with a separate wavelength band. Each wavelength band is then amplified by a Raman pump utilizing a length of highly non-linear fiber as the gain medium, and by an SOA amplifier. The combination of the Raman amplifier and the SOA yields a level gain over the wavelength band. The amplified wavelength band signals are then recombined. The disclosed amplifier is especially useful in coarse wavelength division multiplexing (CWDM) systems and in local access portions of the network.
Claims21
An amplifier system for amplifying a data-bearing optical signal, comprising:
- a signal separator for separating the data-bearing optical signal into a plurality of wavelength bands, the separator having an input for receiving the data-bearing signal and a plurality of separator outputs, each for transmitting one of said wavelength bands;
- a plurality of discrete, hybrid optical amplifiers, said amplifiers being connected in one-to-one correspondence to said separator outputs, each amplifier comprising:
- a discrete Raman amplifier including an optical highly non-linear fiber (HNLF) and a backward-propagating Raman pump laser;
- and
- a semiconductor optical amplifier (SOA) coupled in series with the discrete Raman amplifier;
- and
- a signal recombiner for recombining amplified wavelength bands from the discrete, hybrid optical amplifiers to form an amplified data-bearing signal, the signal recombiner having an output for transmitting the amplified data-bearing signal.
A method for amplifying a data-bearing optical signal, the method comprising the steps of:
- separating the optical signal into a plurality of wavelength band signals, each wavelength band signals being within a different wavelength band;
- transmitting each said wavelength band signal in a forward direction through a separate optical highly non-linear fiber (HNLF);
- introducing a separate backward-propagating Raman pumping signal into each separate HNLF to amplify the wavelength band signal;
- further amplifying each said wavelength band signal using a separate semiconductor optical amplifier (SOA) for each wavelength band signal;
- and
- recombining the plurality of wavelength band signals after amplification by the SOA and Raman pumping signal to form a recombined amplified data-bearing optical signal.
An amplifier system for amplifying data-bearing optical signals in a bidirectional optical transport system, comprising:
- a first signal separator/recombiner for connecting a first bidirectional path segment with a first unidirectional path for transmitting an optical signal in a first direction and a second unidirectional path for transmitting an optical signal in a second direction;
- a first discrete, hybrid optical amplifier in the first unidirectional path, comprising:
- a first discrete Raman amplifier including an optical highly non-linear fiber (HNLF) and a backward-propagating Raman pump laser;
- and
- a first semiconductor optical amplifier (SOA) coupled in series with the first discrete Raman amplifier;
- a second discrete, hybrid optical amplifier in the second unidirectional path, comprising:
- a second discrete Raman amplifier including an optical highly non-linear fiber (HNLF) and a backward-propagating Raman pump laser;
- and
- a second semiconductor optical amplifier (SOA) coupled in series with the second discrete Raman amplifier;
- and
- a second signal separator/recombiner for connecting a second bidirectional path segment with the first unidirectional path and the second unidirectional path.
Dependencies are inferred from the claim text.