Abstract: An optical transmission system allows for the remote determination of the output power of each carrier for each repeater. The optical transmission system includes two terminals, an optical path that transmits a plurality of optical signals between the two terminals, and a plurality of repeaters spaced along the optical path. At least one of the terminals generates a first line monitor signal and a second line monitor signal. The second line monitor signal is delayed by a round trip delay from the terminal to a repeater at which the output power is desired to be measured. The terminal then transmits the first line monitor signal on the optical path. Each repeater in the transmission system generates a return line monitor signal in response to receiving the first line monitor signal and transmits the return line monitor signal on the optical path.

Abstract: A connector assembly is disclosed. In an embodiment for the connector assembly, the assembly includes a shorting plate, a shorting connector, and a connector holder. The connector holder includes a clamp arm and a base. The base is attached to the shorting plate and the shorting connector is disposed between the base and the clamp arm. In an embodiment for the connector, the connector includes a cap block and a socket support dispose on a first side of the cap block. First and second sockets, having a first end and a second end, are disposed on the socket support. The first end of the first socket extends beyond the first end of the second socket. A support block is connected to the cap block wherein the first and second sockets and the socket support are disposed between the support block and the cap block.

Abstract: A trunk and branch logical ring network includes a plurality of nodes that are coupled to a ring backbone by a plurality of branching units. The connections to the ring backbone are such that physically adjacent nodes are not adjacent to one another logically in the network. By providing this alternating branching arrangement the maximum length of any unregenerated span along the ring is significantly reduced. This reduces repeater spacing in the network.

Abstract: A system for protecting optical components is disclosed. The system includes an optical tray with at least one optical component and a cover that can be mounted on the optical tray. The optical tray includes a base with an aperture and a door assembly mounted on the base. The aperture has an area that is sufficiently large for access to components on the optical tray. The door assembly has at least one door having a surface area sufficient to cover at least a portion of the aperture. The cover protects the components and contents of the optical tray against external shock, including mechanical, electrical and electromagnetic impulses, yet allows easy access to these components and contents when desired.

Abstract: An optical fiber cable is provided for undersea applications that include a hollow buffers tube with at least one optical fiber disposed therein. The buffer tube is formed from a plastic material. A water-blockable gel is located in the buffer tube and a series of strength members are configured in a close-packed arrangement around the buffer tube. A metal conductor surrounds the series of strength members and a plastic jacket encapsulating the metal conductor.

Abstract: A device for storing at least one fiber can include at least two of the following components: a separator, a plurality of lifters, and a secluder. The separator can separate a first fiber portion from a second fiber portion of a fiber. The separator can define at least one inner bearing surface adapted to restrain the first fiber portion from straightening when coiled within the separator, and at least one outer bearing surface that can be adapted to limit a path defined by the second fiber portion when coiled on the separator. The path can vary with a longitudinal tension in the second fiber portion, and can have a plurality of curves each having a radius. The radius of each curve of the path can at least meet a reliability-adjusted minimum bending radius of the second fiber portion. The separator can also define at least one separator opening adapted for passing the fiber therethrough. The plurality of lifters can move a plurality of fibers parallel to a spooling axis around which the fibers are spooled.

Abstract: A device for separating a first fiber portion from a second fiber portion of a fiber. The device includes a separator that can define at least one inner bearing surface adapted to restrain the first fiber portion from straightening when coiled within the separator. The separator defines at least one outer bearing surface that can be adapted to limit a path defined by the second fiber portion when coiled on the separator. The path can vary with a longitudinal tension in the second fiber portion. The path can have a plurality of curves each having a radius. The radius of each curve of the path can at least meet a reliability-adjusted minimum bending radius of the second fiber portion. The separator can also define at least one separator opening adapted for passing the fiber therethrough.

Abstract: A gain-clamped, optical amplifier includes a rare-earth doped fiber and a source of pump energy coupled to the rare-earth doped fiber. The doped fiber serves as a gain medium that is optically pumped by the pump source. A wavelength-selective optical feedback loop is coupled between input and output ports of the rare-earth doped fiber. The feedback loop supports a compensating laser signal, which is a pulsed signal located at a wavelength different from a signal wavelength.

Abstract: Optical signals modulated with data are transmitted into a fiber link having a property of including nonlinear distortion of the optical signals as a function of signal power of the optical signals and distance traversed in the fiber link. The data is formatted with multiple-level signaling having a preselected M value to produce formatted data signals. The formatted data signals are multiplexed to produce wavelength-division multiplex (WDM) channels each carrying optical signals based on the formatted data signals. The preselected M value is based on signal jitter and maximum signal power.

Abstract: A device is disclosed for winding an optical fiber. The device includes a mandrel that is connected to a brace. In an operative mode, the brace engages a stabilizer and the stabilizer is releasably fastened to an optical fiber storage assembly. The stabilizer can be releasably fastened to a spool, a hub, or a tray.

Abstract: A method and apparatus is provided for monitoring an optical transmission path through an optical transmission system supporting bidirectional communication between first and second terminals along first and second optical transmission paths. The first transmission path includes at least one optical amplifier located therein. In accordance with the method, a test signal is generated, which is formed by a superposition of first and second optical tones located at first and second wavelengths, respectively. The first and second wavelengths are within the bandwidth of the optical amplifier. The amplitude and phase of the first and second optical tones are arranged so that the test signal has a substantially constant intensity over a modulation cycle of the first and second optical tones. The test signal is transmitted from the first terminal along the first optical transmission path and through the optical amplifier.

Abstract: A system for storing a fiber within a storage space defined by a restrainer. The fiber can have a first fiber portion and a second fiber portion. The system can include a separator that divides the storage space into a first fiber portion storage space and a second fiber portion storage space. The separator can define at least one inner bearing surface adapted to restrain the first fiber portion from straightening when coiled within the first fiber portion storage space. The separator can also define at least one outer bearing surface adapted to limit a path defined by the second fiber portion when coiled within the second fiber portion storage space. The path can vary with a longitudinal tension in the second fiber portion. The path can have a plurality of curves, each having a radius. The radius of each curve of the path can at least meet a reliability-adjusted minimum bending radius of the second fiber portion.

Abstract: A method is provided for locating an intermittent fault occurring in an optical transmission system that includes a plurality of repeaters extending along first and second optical transmission paths for supporting bi-directional communication. In accordance with the method, a measurement is obtained of the gain imparted to a test signal along a round trip path between its originating point and each repeater. For each repeater there are identified changes in gain beyond a prescribed threshold and the time when the gain changes occur. A record of transmission performance data occurring over time is received. The performance data may be a bit error rate, SONET overhead data, or forward error correcting metrics, for example. For each repeater, a correlation in time is established between the identified gain changes and the transmission performance data. A fault location is identified based on the established correlation.

Abstract: 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.

Abstract: A method and apparatus is provided for dispersion mapping that yields improved transmission performance for optical transmission systems by providing a more optimal balance between the reduction of both accumulated chromatic dispersion and nonlinear mixing. In particular, the chromatic dispersion is arranged on both a short length scale (within one amplification period) and a long length scale so that the average dispersion returns to zero. The dispersion management within one fiber span is arranged so that the magnitude of the dispersion is large in the section of the fiber span in which the optical power is large and is small in the section of the fiber span in which the optical power is small. This arrangement reduces both the amount of nonlinear mixing and the accumulated chromatic dispersion within the given fiber span.

Abstract: An apparatus and method for mounting an optical element onto a mounting plate is disclosed. In one embodiment, a mounting support structure defines a plurality of apertures therein. The mounting support structure is positioned between the optical element and the mounting plate with the apertures of the mounting support structure aligning with apertures defined by the optical element and the mounting plate. Connection hardware inserted through the aligned apertures secures the optical element, the mounting support structure, and the mounting plate together.

Abstract: A method and apparatus is provided for compensating for dispersion in a wavelength division multiplexed (WDM) optical communication system. The system includes a transmitting and receiving terminal for transmitting and receiving, respectively, an optical signal having a plurality of channels, and an optical fiber transmission path coupling the first and second terminals. The fiber transmission path has a dispersion substantially equal to zero for a selected channel, positive dispersion for a first set of channels, and negative dispersion for a second set of channels. The method begins by providing positive dispersion compensation to the second set of channels at one of the terminals. Negative dispersion compensation is provided to the first set of channels, also at one of the terminals.

Abstract: A gain-clamped, optical amplifier includes a rare-earth doped fiber and a source of pump energy coupled to the rare-earth doped fiber. The doped fiber serves as a gain medium that is optically pumped by the pump source. A wavelength-selective optical feedback loop is coupled between input and output ports of the rare-earth doped fiber. The feedback loop supports a compensating lasing signal, which is a pulsed signal located at a wavelength different from a signal wavelength.

Abstract: A branching unit is provided for directing individual wavelengths of a WDM optical communication signal among a transmitting terminal, a receiving terminal and a branch terminal. The branching unit includes first and second cross bar switches each having at least a first, second and third port such that in a first state the first cross bar directs an optical signal appearing on the first port to the second port and in a second state the first cross bar directs the optical signal from the first port to the third port. A reflective filter couples the third port of the first switch to the third port of the second switch. The reflective filter is configured to reflect a prescribed wavelength and to transmit therethrough all remaining wavelengths forming the WDM signal. An optical fiber couples the second port of the first switch to the second port of the second switch. First and second circulators are also provided, which each have an input, output and an intermediate port.

Abstract: An apparatus and method for coupling a fiber optic connector is disclosed. In one embodiment for a fiber optic connector wrench in accordance with the present invention, the fiber optic connector wrench includes an engagement portion and a handle member having a first portion with a first longitudinal axis and a second portion with a second longitudinal axis. The engagement portion is rigidly connected to the first portion. A collapsible joint joins the first portion to the second portion where the first longitudinal axis is aligned with the second longitudinal axis when a torque less than a predetermined value is applied to the collapsible joint and where the first longitudinal axis is offset from the second longitudinal axis when a torque greater than or equal to the predetermined value is applied to the collapsible joint.