Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to transmission of large volumes of data over long distances at high rates. An improved method and system for transmitting optical data over long distances using filtered return-to-zero (RZ) modulation format is disclosed. In particular, the improvement teaches the proper optical and electrical filtering of the optical signal at the receiver module.

Abstract: Dispersion compensation is provided in an optical transmission system. An optical line couples first and second transceivers, and a plurality of amplifiers coupled to the optical line are spaced throughout the optical line with variable span distances. A plurality of dispersion compensation modules include a coarse granularity fiber, a connector, and a fine granularity fiber. A memory is associated with the dispersion compensators to provide information related to the value of the dispersion compensation.

Abstract: Dispersion compensation is provided in an optical transmission system. An optical line couples first and second transceivers, and a plurality of amplifiers coupled to the optical line are spaced throughout the optical line with variable span distances. A plurality of dispersion compensation modules include a coarse granularity fiber, a connector, and a fine granularity fiber. A memory is associated with the dispersion compensators to provide information related to the value of the dispersion compensation.

Abstract: Systems and methods for controlling a Raman amplifier by measuring power at one end of an optical fiber span. The Raman amplifier may include a laser that pumps an optical signal into the optical fiber span. The Raman amplifier may be connected to a controller that receives backscatter measurements. The controller may then adjust the Raman amplifier to maintain the backscatter substantially constant.

Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to optical transport systems employing optical amplifiers. In particular the invention teaches an apparatus and method that allows cost effective co-directional operation of an optical amplifier to support full duplex traffic on a single fiber, and the design of an optical fiber transmission system based on this optical amplifier technology.

Abstract: An automated optical transport system is provided which provides for automatic discovery of system components, automatic inventory of system components, automatic topology detection, automatic provisioning of channels, and automatic characterization and tuning of system components and fiber. The invention provides automation capability through inclusion of management card capabilities at each station which communicates through a reverse propagating service channel. Dynamic and propagation direction independent segments are provided in conjunction with a token-based scheme to repeatedly tune, update and monitor the transport system.

Abstract: The invention provides for optical circulators which redirect light from port to port sequentially in one direction used to separate traffic in a bidirectional optical fiber transmission system. The invention provides for using two optical circulators in each span of bidirectional fiber so that the OSC channel can be transmitted in one direction opposite to the WDM channels. The invention also provides for a gigabit Ethernet path between chassis which is utilized for control traffic and customer traffic. The invention is placed in a non-critical region of the optical spectrum and is independent of all other chassis equipment. The invention also provides the advantage in alternate embodiments of providing the option of a second counter propagating WDM channel being transmitted along with the OSC to provide additional system capacity. The invention also provides the advantage in an alternate embodiment of allowing the OSC to be amplified through a raman source without the need of complete system retrofit.

Abstract: An automated optical transport system is provided which provides for automatic discovery of system components, automatic inventory of system components, automatic topology detection, automatic provisioning of channels, and automatic characterization and tuning of system components and fiber. The invention provides automation capability through inclusion of management card capabilities at each station which communicates through a reverse propagating service channel. Dynamic and propagation direction independent segments are provided in conjunction with a token-based scheme to repeatedly tune, update and monitor the transport system.

Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to transmission of large volumes of data over long distances at high rates. An apparatus and method for improved bit-error-rate (BER) performance when transmitting optical data over long distances using is disclosed. In particular, the improvement teaches the proper decision threshold setting of the optical signal at the receiver module.

Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to optical transport systems employing Raman optical amplifiers. In particular the invention teaches an apparatus and method to control the Raman gain based upon power measurements at one end of the transmission fiber.

Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to transmission of large volumes of data over long distances at high rates. An improved apparatus and method for measuring dispersion in a fiber span is disclosed. In particular, the invention teaches a highly accurate technique for measuring the fiber dispersion at a single wavelength. Transmitter and receiver structure and data processing algorithms are disclosed.

Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to transmission of large volumes of data over long distances at high rates. An improved apparatus achieving precise dispersion compensation in a fiber span is disclosed. In particular, the invention teaches a configurable dispersion compensation trimmer with automatic detection of configuration.

Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to transmission of large volumes of data over long distances at high rates. An improved apparatus achieving precise dispersion compensation in a fiber span is disclosed. In particular, the invention teaches a configurable dispersion compensation trimmer with automatic detection of configuration.

Abstract: A method and apparatus for adjusting the tilt of an inline amplifier. A controller reads the power of an amplifier twice. Then, if there is a change in power, a difference is calculated by subtracting the first power from the second power. A tilt correction is calculated by multiplying the change in power by a negative constant. The system then adjusts a gain control device by the tilt correction. Because of the simplicity of the algorithm and location of the controller, adjustments can be made to the gain tilt within approximately 100 ?s and system failures can be avoided.

Abstract: A method and apparatus for adjusting the tilt of an inline amplifier. A controller reads the power of an amplifier twice. Then, if there is a change in power, a difference is calculated by subtracting the first power from the second power. A tilt correction is calculated by multiplying the change in power by a negative constant. The system then adjusts a gain control device by the tilt correction. Because of the simplicity of the algorithm and location of the controller, adjustments can be made to the gain tilt within approximately 100 ?s and system failures can be avoided.

Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to optical transport systems employing optical amplifiers. In particular the invention teaches an apparatus and method that allows cost effective co-directional operation of an optical amplifier to support full duplex traffic on a single fiber, and the design of an optical fiber transmission system based on this optical amplifier technology.

Abstract: A method and apparatus for adjusting the tilt of an inline amplifier. A controller reads the power of an amplifier twice. Then, if there is a change in power, a difference is calculated by subtracting the first power from the second power. A tilt correction is calculated by multiplying the change in power by a negative constant. The system then adjusts a gain control device by the tilt correction. Because of the simplicity of the algorithm and location of the controller, adjustments can be made to the gain tilt within approximately 100 ?s and system failures cam be avoided.

Abstract: The invention pertains to optical fiber transmission systems, and is particularly relevant to optical transport systems employing Raman optical amplifiers. In particular the invention teaches an apparatus and method to provide initial tuning of a Raman pump module. In the present invention, improvements to Raman gain control are taught in order to provide for an advantageous Raman gain spectral profile.

Abstract: Dispersion compensation is provided in an optical transmission system. An optical line couples first and second transceivers, and a plurality of amplifiers coupled to the optical line are spaced throughout the optical line with variable span distances. A plurality of dispersion compensation modules include a coarse granularity fiber, a connector, and a fine granularity fiber. A memory is associated with the dispersion compensators to provide information related to the value of the dispersion compensation.

Abstract: A power equalization system and method for use in an optical transmission system are provided. The power equalization system includes an optical line including at least one transmission channel and a management line. The transmission system further includes a plurality of amplifiers, a plurality of Optical spectrum analyzers and a plurality of equalizers. The plurality of amplifiers are coupled to the optical line, spaced periodically throughout the optical transmission system. As information is sent through the optical transmission system, the plurality of amplifiers boost the power of each channel of the optical signal. A plurality of optical spectrum analyzers are also coupled to the optical lien and are spaced periodically throughout the optical transmission system and are co-located with a first portion of the amplifiers coupled to the optical line.