Tyco Telecommunications (us) Inc.

Tyco Submarine Systems Ltd.

Tycom (us) Inc.

Other

Lucent Technologies Inc.

Howard D Kidorf

Franklin Webb Kerfoot, Iii

Karsten Rottwitt

Xiaobing Ma

Morten Nissov

Georg Heinrich Mohs

Ekaterina A Golovchenko

Stuart M Abbott

Robert L Lynch

Michael Vaa

Bamdad Bakhshi

Kenneth L Walker

Bo Pedersen

Nandakumar Ramanujam

Xiabing Ma

Donald G Duff

Dimitri Foursa

Alexei Pilipetski

An apparatus and method directed to testing and optimizing performance of an optical transmission system is disclosed, including at least one broadband dispersion compensation unit (DCU) or at least one depolarization device. The depolarization device may be used alone or in combination with the at least one broadband DCU. A method for optimizing performance of data channels in initial loading (IL) and full loading (FL) configurations of the optical transmission system is also disclosed.

Apparatus and method for commissioning an optical transmission system

A method and apparatus for performing error correction is described. A stream of data is encoded using concatenated error correcting codes. The encoded data is communicated over a transmission system. The encoded data is decoded using the codes and three levels of decoding.

Concatenated forward error correction decoder

A lightwave communication system is provided that includes first and second optical transmitters/receivers remotely located with respect to one another. First and second optical transmission paths couple the first transmitter/receiver to the second transmitter/receiver for bidirectionally transmitting optical information therebetween. First and second doped optical fibers are respectively disposed in the first and second optical transmission paths. Optical pump energy is supplied by first and second optical pump sources. The first optical pump source generates Raman gain in the first transmission path and the second optical pump source generates Raman gain in the second transmission path. A first optical coupler is provided for optically coupling pump energy from the first pump source to the second-doped optical fiber and a second optical coupler is provided for optically coupling pump energy from the second pump source to the first doped optical fiber.

Optical fiber communication system employing doped optical fiber and Raman amplification

A Raman amplifier is provided that includes at least a portion of optical fiber in which an optical signal travels. The optical fiber portion may encompass all or part of the optical transmission path of an optical communication system. A pump energy unit is provided that includes at least three pump sources providing pump power at different pump wavelengths. The different pump wavelengths are spaced apart from one another by nonuniform amounts so that a prescribed Raman gain profile is generated in the optical fiber portion. An optical coupler is provided for coupling the pump power to the optical fiber portion and transmitting the optical signal therethrough.

Wide bandwidth raman amplifier having a substantially flat gain profile

A method and apparatus to amplify an optical signal is described. A first filter splits an optical signal into a first and second parts. A first raman amplifier amplifies the first part. A second raman amplifier amplifies the second part. A combiner combines the amplified first and second parts.

Method and apparatus to perform lumped raman amplification

A Raman amplifier is provided that includes at least a portion of optical fiber in which an optical signal travels. The optical fiber portion may encompass all or part of the optical transmission path of an optical communication system. A pump energy unit is provided that includes first and second pump sources providing pump power at first and second wavelengths, respectively. The first and second wavelengths generate first and second gain profiles in the optical fiber portion. The first and second gain profiles overlap in wavelength. An optical coupler couples the pump power to the optical fiber portion. Since the gain profiles overlap, the Raman amplifier has a greater bandwidth than can be achieved with a pump operating at a single wavelength.

Wide bandwidth Raman amplifier employing a pump unit generating a plurality of wavelengths

A method and apparatus provides pump energy to an optical fiber located along an optical transmission path. The optical fiber imparts Raman amplification to an optical signal traveling therein when pumped at a pump wavelength. In accordance with the method, a first beam of pump energy is generated at the pump wavelength of the optical signal and a second beam of pump energy at a wavelength one Raman Stokes order below the pump wavelength. The first beam of pump energy is introduced to the optical fiber so that it contrapropagates with respect to the optical signal. The second beam of pump energy is introduced to the optical fiber so that it co-propagates with respect to the optical signal. The second beam of pump energy does not pump the signal (thus minimizing noise) but rather serves to pump the first pump beam by the production of Raman Stokes- shifted light.

Low noise Raman amplifier employing bidirectional pumping and an optical transmission system incorporating same

A method is provided for determining at least one optical transmission parameter for achieving a prescribed operating characteristic of an optical transmission system that includes at least one optical amplifier. The optical transmission parameter to be determined may include, for example, the channel wavelengths that are employed, the channel powers, and/or the spacing between adjacent channels. The method begins by transmitting through the transmission system a plurality of saturating optical wavelengths such that the optical amplifiers operate at a desired operating point within a region of gain compression. A plurality of probe wavelengths are transmitted through the transmission system. The probe wavelengths have a total power insufficient to substantially change the desired operating point of the optical amplifiers. The plurality of probe wavelengths are characterized by at least one optical transmission parameter. Next, an initial operating characteristic of the transmission system is determined. The optical transmission parameter of the plurality of probe wavelengths is then varied to determine a second operating characteristic of the transmission system. The steps of determining an initial operating characteristic and varying the optical transmission parameter is repeated until a resulting operating characteristic of the transmission system is substantially equal to the prescribed operating characteristic.

Method for determining transmission parameters for the data channels of

A method and apparatus is provided for providing pump energy to a doped optical fiber located along an optical transmission path. The doped optical fiber imparts amplification to an optical signal when pumped at a pump wavelength. In accordance with the method, pump energy is generated in the transmission fiber by introducing a power at a wavelength one Raman Stokes order below the desired pump wavelength. The pump energy is transmitted along the transmission path such that first order Raman Stokes-shifted light is applied to the doped optical fiber. For example, if the optical fiber is doped with erbium, which has a pump wavelength of about 1485 nm, pump energy is provided at a wavelength of 1390 nm.

Method of apparatus for remotely pumping a rare-earth doped optical

A high-powered optical pump includes at least two sub-pumps. Each sub-pump generates light at different wavelengths. The outputs of the sub-pumps are coupled to a remote pump fiber. The resulting light transmitted on the remote pump fiber results in a lower Raman gain and Raman noise spectral peak than that generated by existing single wavelength high-powered optical pumps at the same power level. Therefore, increased power can be transmitted on the remote pump fiber in contrast to a single wavelength pump. Additionally, the total gain spectrum available for the amplification of signals is increased.

Multi-wavelength optical pump

The disclosed optical fiber communication system comprises a remotely pumped erbium-doped fiber amplifier (EDFA). The pump radiation is de-tuned with respect to wavelength, the wavelength being selected longer than both the optimal wavelengths for pumping the EDFA and for producing Raman gain in the transmission fiber, respectively. Such de-tuning results in improved over-all system performance through reduced multi-path interference. Exemplarily, the pump radiation has wavelength in the range 1490-1510 nm.

Optical fiber communication system with a distributed Raman amplifier

A Raman amplifier is provided that includes at least a portion of optical fiber in which an optical signal travels. The optical fiber portion may encompass all or part of the optical transmission path of an optical communication system. A pump energy unit is provided that includes first and second pump sources providing pump power at first and second wavelengths, respectively. The first and second wavelengths generate first and second overlapping gain profiles in the optical fiber portion. An optical circulator has a first port receiving the pump power, a second port providing the pump power to the optical fiber and receiving the optical signal, and a third port transmitting the optical signal received from the second port. As a result of this arrangement, a Raman amplifier is provided in which the bandwidth is substantially increased over the bandwidth that can be achieved by the previously mentioned Raman amplifier.

Wide bandwidth Raman amplifier capable of employing pump energy

A path couples a pair of optical fibers in an optical transmission system. The transmission system includes a plurality of optical amplifiers placed along the transmission line. Associated with these optical amplifiers are optical isolators that limit the flow of optical energy to a single direction. The path allows reflected or scattered light from one optical fiber after the optical isolator to be returned via the other optical fiber. This enables an OTDR device to obtain measurement information along the entire length of the fibers between optical isolators.

Path to provide OTDR measurements of an optical transmission system that

In a fiber optic assembly that is sealed within an enclosure and that has a plurality of optical transmission paths available to transmit input signals through the assembly, a separate link is provided for each transmission path. Each of the separate links has a first end that is located external to the sealed enclosure and a second end that is located within the enclosure and adjacent to the link's associated transmission path. The link is capable of transmitting energy from an energy source coupled to the link at the first end through the link to the second end. The energy is received at the second end of the link, where the second end's proximity to its associated optical transmission path allows the energy to act on the transmission path to render the path inoperable for transmitting an input signal along the path and through the assembly. As such, the fiber optic assembly is configured to permit selected input signals to be transmitted through the fiber optic assembly to a particular destination based upon the requirements of the communication system into which it is integrated.

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Red Bank, NJ, United States of America

Howard D Kidorf