Abstract: Repeaters for use in amplifying optical data signals transmitted through undersea fiber optic cables are disclosed. Raman amplification schemes using 100 or more pump lasers are integrated into industry standard sized pressure vessels for amplifying optical data signals transmitted through one or more fiber optic pairs. Such repeaters include high density packaging to permit numerous active and passive optical components, as well as significant lengths of optical fiber, to reside within legacy sized pressure vessels.

Abstract: A system compensates for the presence of power transients. The system receives a data signal and detects the occurrence of a power transient. The system generates a threshold signal based on the detected power transient and determines a value of the data signal based on the threshold signal.

Abstract: A hybrid interface for handling different types of data streams is disclosed. Both OC192 and OC768 data streams can be transported between terrestrial and submarine systems using hybrid interfaces. Examples include processing branches that use common FEC units, multiplexers, demultiplexers, transmitters and receivers for both types of data streams. WDM channels are allocated in groups for OC768 data stream handling. Time misalignment between received channels within a group is identified and compensated.

Abstract: A system and method for protecting from the loss of data in an optical data network includes receiving the data over a service optical fiber line, delaying reception of the data over a protection optical fiber line by a first delay amount with respect to the reception of the data over the service optical fiber line, and detecting a fault condition in the service optical fiber line. In response to the detection of the fault condition, the transmission of data over the protection optical fiber line is received. The first delay amount corresponds to at least the amount of time to switch to the reception of the data over the protection optical fiber line from the reception of the data over the service optical fiber line after the detection of the fault condition.

Abstract: A branch unit for a fiber optic system that includes a service path and a protection path, whereby the branch unit provides switching to account for problems due to fiber cuts and/or equipment failures that may occur in the fiber optic system. The service and protection paths meet at a branch point of the fiber optic network, or at a network protection equipment (NPE) that is located near a customer interface equipment. A plurality of switches are provided at the branch unit or NPE, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path.

Abstract: A method and system for generating both return-to-zero (RZ) and carrier suppressed return-to-zero (CSRZ) shaped signals using only a single optical modulator. The system includes: a switch for receiving a data signal and a clock signal as inputs, and outputting a voltage signal; a unit for controllably adjusting the phase of said clock signal before input to the switch; an optical modulator for receiving a continuous wave light (CW) signal and the voltage signal as inputs, and outputting one of an RZ and a CSRZ signal. To generate a CSRZ signal, the optical modulator is biased at a transmission minimum level signal. To generate an RZ signal, the optical modulator is biased at a transmission maximum level and the clock signal is phase shifted. Also disclosed is an optical communication transceiver including a plurality of optical modulator circuits generating both RZ and CSRZ signals.

Abstract: A method for maintaining amplifier saturation in a wavelength division multiplexed (WDM) optical network having a plurality of sub-bands, each sub-band including at least two signal channels which carry respective data signals, and a plurality of substitute signal transmitters, each substitute signal transmitter generating a substitute signal and corresponding to a respective one of the plurality of sub-bands, includes identifying signal channels having a predetermined characteristic within each of the plurality of sub-bands. A substitute signal transmitter is turned on if the sub-band corresponding to the substitute signal transmitter includes a predetermined number of signal channels having said predetermined characteristic. The data signals and the substitute signals are combined into a WDM signal, and the WDM signal is transmitted over an optical transmission fiber.

Abstract: A collapsed ring fiber optic system includes a service path and a protection path provides at a shallow water portion of the fiber optic system, to deal with any fiber cuts that may occur at the shallow water portion without loss of main trunk bandwidth. The service and protection paths meet at a branch point, which is preferably located at a deep water portion of the fiber optic system. A passive combiner or a 1×2 switch is provided at the branch unit, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path. At another shallow water portion of the fiber optic system, nearby where a destination is located, the signal provided on the optical path over the deep water portion is split into a service path and a protection path, to provide redundancy to deal with any fiber cuts that may occur.

Abstract: A wavelength division multiplexed (WDM) optical network includes a plurality of optical transmitters, each optical transmitter generating a data signal sent over a respective one of a plurality of signal channels, the plurality of signal channels being divided into a number of sub-bands where each sub-band includes at least two signal channels, and a plurality of substitute signal transmitters, the number of substitute signal transmitters being equal to the number of sub-bands, each substitute signal transmitter generating a substitute signal which provides loading in a corresponding sub-band. The WDM optical network also includes a combining circuit which combines the data signals output from the plurality of optical transmitters and the substitute signals output from the plurality of substitute signal transmitters into a WDM signal, and an optical transmission fiber which receives the WDM signal from the combining circuit.

Abstract: A method of amplifying optical signals comprising providing a plurality of input radiation signals into the inputs of a P×V coupler, each of the input radiation signals having a respective input radiation profile having a set of pump wavelengths and pump powers corresponding to the respective wavelengths, wherein at least one set is different from at least one other set; providing V output pump radiation profiles from the outputs of the P×V coupler; and amplifying an optical data signal by coupling at least one of the V output pump radiation profiles with the optical data signal, wherein at least one of the V output pump radiation profiles has a different power than at least one other of the V output pump radiation profiles.

Abstract: A branch unit for a fiber optic system that includes a service path and a protection path, whereby the branch unit provides switching to account for problems due to fiber cuts and/or equipment failures that may occur in the fiber optic system. The service and protection paths meet at a branch point of the fiber optic network, or at a network protection equipment (NPE) that is located near a customer interface equipment. A plurality of switches are provided at the branch unit or NPE, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path.

Abstract: A laser system includes a series coupled laser diode pair, first and second current regulators, and a power supply. The first current regulator controls current supplied to the laser diode pair. The second current regulator selectively diverts a portion of the supplied current away from a first laser diode of the laser diode pair. The power supply adaptively adjusts a level of a supply voltage applied across the series coupled laser diode pair.

Abstract: A method of modulating an optical signal is provided comprising the steps of providing a first electric field in a first optical signal path, providing a second electric field in a second optical signal path, transmitting an optical signal along the first optical signal path and the second optical signal path, amplitude modulating the optical signal via the first electric field and the second electric field, and phase modulating the optical signal via the first electric field and the second electric field. A clock source and a data source are ANDed to provide a data modulated RF signal on an offset waveguide electrode for generating the first and second electric fields. The magnitude of the electric field of the first electric field in the first optical signal path is greater than the magnitude of the electric field of the second electric field in the second optical signal path.

Abstract: An optical transmission system includes a number of corresponding modular multiplexing and demultiplexing units used in transmitting and receiving an optical signal respectively. Additionally, compensation components compensate for optical dispersion experienced by the optical signal. The modular multiplexing and demultiplexing units are assembled in a cascade fashion at the transmit side and the receive side of the optical transmission system, respectively. The dispersion compensation components share dispersion compensation fiber across the cascaded units.

Abstract: A retainer includes a device having at least one dovetail-shaped portion, a frame configured to receive the dovetail-shaped portion, and at least one expanding device. The expanding device is configured to compress the dovetail-shaped portion against the frame, thereby securing the device against the frame.

Abstract: An optical amplifier is described that can couple to and amplify optical signals along multiple fiber transmission paths. The optical amplifier includes a plurality of pump radiation sources, each pump radiation source adapted to produce radiation having a set of pump wavelengths and pump powers corresponding to the respective pump wavelengths, wherein at least one set is different from at least one other set. The optical amplifier also includes a plurality of pump radiation combiners, each pump radiation combiner coupling the radiation of a respective set of pump wavelengths of a respective source of the plurality of pump radiation sources and outputting the respective coupled radiation having coupled radiation profiles via a respective pump radiation combiner output. The optical amplifier also includes a coupler, such as a PxV coupler with P inputs and V outputs.

Abstract: A pump assembly for an optical amplifier includes a plurality of pump radiation sources, each pump radiation source producing radiation at a respective one of a first number of pump wavelengths. A coupler is optically coupled to each of the plurality of pump radiation sources, receives each of the first number of pump wavelengths from the plurality of pump radiation sources, and outputs each of the first number of pump wavelengths to each one of a second number of outputs. The pump assembly also includes a plurality of pump signal combiners, each pump signal combiner optically coupled to a respective one of the second number of outputs of the coupler and receiving each of the first number of pump wavelengths output from the coupler. Each pump signal combiner placing each of the first number of pump wavelengths output from the coupler in co-propagation with a respective one of a plurality of data signals propagating on a respective one of a plurality of optical fibers.

Abstract: An optical fiber winding apparatus includes a base, a plurality of fiber containment devices connected to the base, and a fiber guider connected to and movable in a repeatable path with respect to the base, wherein the guider winds the fiber around the fiber containment devices. The apparatus is hand-held, and the path of the guider overlaps itself in a single cycle of the path, such as a figure-eight.

Abstract: An optical coupler system is described. The optical coupler system is for coupling radiation from a plurality of radiation sources. The optical coupler system comprises a first optical coupler having at least a first and a second input and a first and a second output. The optical coupler also comprises a second optical coupler having at least a first and a second input and a first and a second output, wherein the first and second outputs of the first optical coupler are connected to the first and second inputs, respectively, of the second optical coupler via first and second optical links, and wherein the first and second links provide different optical paths between the first and second optical couplers such that portions of radiation energy that is input to the first input of the first optical coupler are combined incoherently at the first output of said second optical coupler.

Abstract: A collapsed ring fiber optic system includes a service path and a protection path provides at a shallow water portion of the fiber optic system, to deal with any fiber cuts that may occur at the shallow water portion without loss of main trunk bandwidth. The service and protection paths meet at a branch point, which is preferably located at a deep water portion of the fiber optic system. A passive combiner or a 1×2 switch is provided at the branch unit, along with a detector and a processor, to determine whether any signals are being received from the service path, and if not, to reconfigure the system to accept signals from the protection path. At another shallow water portion of the fiber optic system, nearby where a destination is located, the signal provided on the optical path over the deep water portion is split into a service path and a protection path, to provide redundancy to deal with any fiber cuts that may occur.