Abstract: A common component assembly is provided for a cable joint for joining a first submarine optical cable and a second submarine optical cable. The assembly includes a first end face including a first opening and a first flange for connection to a first cable termination unit of an undersea optical cable joint. The assembly also includes a second end face including a second opening and a second flange for connection to a second cable termination unit of an undersea optical cable joint. The assembly further includes a fiber tray connecting the first end face to the second end face. In addition, the assembly includes an optical assembly connected to a first side of the fiber tray. The optical assembly includes a free space optical add/drop multiplexer.

Abstract: An optical repeater is disclosed, comprising: an optical input port for receiving an input optical signal; an optical output port for transmitting an output optical signal; electronics comprising an amplifier configured to increase a signal level of the optical signal between the input port and the output port; a voltage regulator configured to provide a variable voltage power supply to the electronics, and optionally comprising a local or external controller configured to determine a supply voltage in response to demand and to control the voltage regulator to provide the supply voltage.

Abstract: A system includes (i) an optical link including multiple spans of optical fiber and multiple network elements and (ii) at least one switch configured to reverse a direction that at least one of the network elements communicates over the optical link.

Abstract: An apparatus includes an optical amplifier configured to receive an input optical signal and generate an amplified output optical signal. The optical amplifier includes multiple amplifier stages including at least a first amplifier stage and a second amplifier stage. The apparatus also includes a gain clamp configured to accumulate optical power from the first amplifier stage after an optical power level of the input optical signal drops and provide a first portion of the accumulated optical power to the first amplifier stage to clamp a gain applied by the first amplifier stage. The gain clamp is also configured to provide a second portion of the accumulated optical power to the second amplifier stage to adjust a gain applied by the second amplifier stage. The second amplifier stage is configured to amplify the second portion of the accumulated optical power.

Abstract: An apparatus includes a first optical coupler configured to duplicate an optical signal carried by a first cable in a second cable and a third cable. The apparatus also includes a second optical coupler configured to combine an optical signal carried by the second cable and an optical signal carried by the third cable in the first cable. The apparatus further includes an electrical switch configured to selectively connect electrical conductors of the first, second, and third cables.

Abstract: An optical communications apparatus is configured to be connected to first, second, and third optical cables. In a branch connecting configuration, a branch optical path is enabled so that (i) signal wavelengths received over the first cable are routed to the third cable and (ii) signal wavelengths received over the third cable are routed to the second cable. The signal wavelengths received over the third cable include at least one of the signal wavelengths routed from the first cable to the third cable and returned via a loop connection at a distal portion of the third cable. In a bypass configuration, a connection via the branch optical path to the distal portion of the third cable is bypassed so that the signal wavelengths received over the first cable are routed to the second cable without first being routed through the distal portion of the third cable.

Abstract: An apparatus includes multiple ports configured to be coupled to multiple optical fibers and to transmit first optical signals and receive second optical signals over the optical fibers. The apparatus also includes a signal source configured to generate a first additional optical signal for inclusion with the first optical signals. The apparatus further includes a signal detector configured to detect a second additional optical signal included with the second optical signals. In addition, the apparatus includes a switch configured to selectively couple the signal source to one of the ports. The switch is configured to couple the signal source to different ones of the ports in different configurations of the switch.

Abstract: A submarine optical repeater includes a submarine amplifier module, which further includes a pumping laser module and an optical detector module. The pumping laser module generates optical amplifications within an optical cable, and, in the case of a fault in the optical cable, the optical detector module detects at least one characteristic of an optical signal caused by the fault in the optical cable. This configuration then identifies a particular signal characteristic that indicates a fault within the optical cable.

Abstract: An optical communications apparatus includes a branching unit and a switching module. The branching unit is configured to be connected to first, second, and third optical cables each including an optical fiber. The branching unit includes a branch optical path configured to route a fixed pre-determined range of wavelengths that are input to the branching unit from the optical fiber of the first cable to the optical fiber of the third cable. The switching module includes at least one optical switch having a bypass configuration and a branch connecting configuration. In the bypass configuration, a connection via the branch optical path to a distal portion of the third cable is bypassed. In the branch connecting configuration, the branch optical path is enabled so that the pre-determined range of wavelengths that are input to the branching unit are routed to the optical fiber of the distal portion of the third cable.

Abstract: An apparatus includes first bidirectional communications equipment having a transmitter and a receiver. The first bidirectional communications equipment is configured to operate in at least a first configuration and a second configuration. In the first configuration, the first bidirectional communications equipment is configured to provide a bidirectional communication link with a transmitter and a receiver of second bidirectional communications equipment. In the second configuration, the first bidirectional communications equipment is configured to provide (i) a first unidirectional communication link between the transmitter of the first bidirectional communications equipment and the receiver of the second bidirectional communications equipment and (ii) a second unidirectional communication link between the receiver of the first bidirectional communications equipment and a transmitter of third bidirectional communications equipment.

Abstract: An apparatus includes bidirectional communication equipment for communicating information along optical fibers, where the bidirectional communications equipment is configured to provide a first unidirectional communication link from the equipment to a first location and a second unidirectional communication link to the equipment from a different second location.

Abstract: An apparatus includes a remote optically pumped amplifier (ROPA). The ROPA includes a bypass filter configured to receive an optical signal and first pump power and to separate the optical signal and the first pump power. The ROPA also includes an amplifier configured to receive the optical signal from the bypass filter and to amplify the optical signal. The ROPA further includes an optical combiner/multiplexer configured to receive the first pump power from the bypass filter, receive at least second and third pump powers, combine at least two of the first, second and third pump powers, and provide different pump powers or combinations of pump powers to different locations within the ROPA to feed the amplifier.

Abstract: An optical communications apparatus includes a subsea cable, first and second landing stations, a splitter/combiner unit connected to an end of the subsea cable, and first and second legs connecting the splitter/combiner unit to the first and second landing stations, respectively. Each of the subsea cable and first and second legs includes an optical fiber configured to carry optical communications and an electrical conductor configured to carry electrical power. The splitter/combiner unit is configured to duplicate optical signals carried by the subsea cable in both the first and second legs. The first and second legs are configured to provide redundant electrical power connections to the subsea cable via the splitter/combiner unit.

Abstract: An optical communication link that includes two nodes interconnected by an optical channel that comprises optical fiber(s), and that is used to communicate an optical signal comprising multiple optical signal wavelengths. The first node provides an optical signal onto the optical channel towards the second node, or receives an optical signal from the optical channel from the second node. A Raman pump provides Raman pump power into the optical fiber of the optical channel to thereby perform Raman amplification of the optical signal in the optical fiber. The second node determines a quality measurement of at least of optical wavelength signals transmitted by the first node to the second node. The second node also transmits information from the quality measurement back to the first node. A controller at the first node controls at least one parameter of the Raman pump in response to this transmitted information.

Abstract: An apparatus includes a remote optically pumped amplifier (ROPA). The ROPA includes a bypass filter configured to receive an optical signal and first pump power and to separate the optical signal and the first pump power. The ROPA also includes an amplifier configured to receive the optical signal from the bypass filter and to amplify the optical signal. The ROPA further includes an optical combiner/multiplexer configured to receive the first pump power from the bypass filter, receive at least second and third pump powers, combine at least two of the first, second and third pump powers, and provide different pump powers or combinations of pump powers to different locations within the ROPA to feed the amplifier.

Abstract: A submarine optical repeater includes a submarine amplifier module, which further includes a pumping laser module and an optical detector module. The pumping laser module generates optical amplifications within an optical cable, and, in the case of a fault in the optical cable, the optical detector module detects at least one characteristic of an optical signal caused by the fault in the optical cable. This configuration then identifies a particular signal characteristic that indicates a fault within the optical cable.

Abstract: A remote optically pumped amplifier in a multi-span optical communications link. A backwards Raman pump module performs backwards Raman amplification in an optical communications span that contains the remote optically pumped amplifier. A residual amount of backwards Raman pump power is then used to power the remote optically pumped amplifier. The remote optically pumped amplifier may be located 40 to 120 kilometers in optical distance from the backwards Raman pump module such that at least three milliwatts of residual Raman pump power is received by the remote optically pumped amplifier. The Raman pump module may be a multi-pump Raman pump module. A controller controls pump power provided by at least one of the pumps of the backwards Raman pump module, so as to at least partially compensate for optical signal strength versus wavelength variation introduced by the remote optically pumped amplifier and the backwards Raman pump module.