Abstract: A branching unit includes a supply destination switching section that switches one supply destination of each of a plurality of power lines that supply electric power to a unit that transfers an optical signal received from a terminal station unit through a transmission line to another supply destination corresponding to a control signal received from the terminal station unit; a current detection section that outputs a detection signal that includes information that denotes whether currents are flowing in the plurality of power lines and information that represents current directions if currents are flowing; and a monitor section that transmits a monitored result based on at least one of a plurality of detection signals received from the current detection section to the terminal station unit.

Abstract: Methods and systems for optical communication in a submarine network are provided. An input signal is received from a terminal at a reconfigurable branching unit (BU), and the input signal is split into at least two parts, with one part being associated with one or more trunk terminals and another part being associated with one or more branch terminals. Each of one or more spectrum channels are selected and individually switched to one of a plurality of paths using at least one wavelength selective switch (WSS), with the at least one WSS being configured to transmit the one or more spectrum channels to their respective target output port and to combine signals switched to a specific port into a wavelength division multiplexing (WDM) signal. Individual spectrum channels are filtered out using at least one wavelength blocker (WB).

Abstract: Systems and methods for method for data transport using secure reconfigurable branching units, including receiving signals from a first trunk terminal and a second trunk terminal by branching units. Broadcasting is prevented for secure information delivery by dividing, within the branching units, the one or more signals from the first trunk terminal and the second trunk terminal into two or more sections, and sending the two or More sections to an optical coupler. Signals may be received from a branch terminal by one or more branching units using two fiber pairs, and the signals from the branch terminals may be divided into two or more groups of optical sections, wherein one of the sections includes dummy light. The divided, signals from the first trunk terminal, the second trunk terminal, and dummy light from the branch terminal may be merged, and the merged signal sent to the branch terminal.

Abstract: Systems and methods for method for data transport using secure reconfigurable branching units, including receiving signals from a first trunk terminal and a second trunk terminal by branching units. Broadcasting is prevented for secure information delivery by dividing, within the branching units, the signals from the first trunk terminal and the second trunk terminal into three or more sections. Signals may be received from a branch terminal by one or more branching units using a single branch fiber pair, and the signals from the branch terminals may be divided into three or more groups of optical channels, wherein at least e of the channels includes dummy light. The divided signals from the first trunk terminal, the second trunk terminal, and dummy light from the branch terminal may be merged, and the merged signal sent to the branch terminal.

Abstract: Methods and systems for optical communication in a submarine network are provided. An input signal is received from a terminal at a reconfigurable branching unit (BU), wherein the BU enables bidirectional transmission between any two terminals, and the input signal is demultiplexed into at least one individual waveband or wavelength using at least one demultiplexer. Each demultiplexed waveband is passed through optical switches, with corresponding optical switches for the same demultiplexed waveband provided for transmission in the reverse direction. Independent per-waveband switching is performed using a demultiplexer-switch-multiplexer (DSM) architecture. Each demultiplexed waveband is multiplexed at each output port using at least one multiplexer to combine signals from different sources, and combined signals are transmitted to a destination terminal.

Abstract: Systems and methods for data transport, including submarine reconfigurable optical add/drop multiplexers, branching units configured to receive signals from trunk terminals (TTs), and dummy light filters configured to pass useful signals through the filters, and to reflect dummy light. Optical interleavers are configured to separate useful signals into two or more groups of optical channels, and the optical channels are set to a frequency of either a left or a right portion of a total channel bandwidth. De-interleavers merge signal groups together from trunk terminals, and lasers at each of the transponders at the source terminals are configured to adjust a destination of a channel by fine tuning a frequency or wavelength of the one or more signals.

Abstract: A branching unit includes a supply destination switching section that switches one supply destination of each of a plurality of power lines that supply electric power to a unit that transfers an optical signal received from a terminal station unit through a transmission line to another supply destination corresponding to a control signal received from the terminal station unit; a current detection section that outputs a detection signal that includes information that denotes whether currents are flowing in the plurality of power lines and information that represents current directions if currents are flowing; and a monitor section that transmits a monitored result based on at least one of a plurality of detection signals received from the current detection section to the terminal station unit.

Abstract: A submarine network includes a submarine network with a branching unit BU for splitting or combining a signal between a main trunk path and a branch path for allowing signals from different paths to share a same fiber optic path, said BU and submarine network normally having a fixed and predetermined wavelength arrangement preventing reconfigurability of the submarine network, and a latching wavelength selective switch WSS or wavelength blocker WB in the branching unit for splitting or combining the signals between the main trunk path and branch path to enable a latching capability and enable reconfigurability of the branching unit BU, the latching WSSS being a bistable liquid crystal based material without moving parts for increased stability and lower power consumption over use of conventional mono-stable liquid crystal LC switches in a submarine network.

Abstract: The present invention does not require control and path switching by terminal station equipment and prevents the deterioration of signal quality when a cable failure occurs. A wavelength diverging device connected with three or more stations monitors an uplink signal received from each station, and when detecting the absence of an uplink signal received from any station, outputs dummy light instead of the absent signal, performs multiplexing/de-multiplexing for the dummy light and an uplink signal received from a station excluding said any station, and outputs the multiplexed/de-multiplexed signal. All of said processes are performed within the wavelength diverging device.

Abstract: Methods and systems for optical communication in a submarine network are provided. An input signal is received from a terminal at a reconfigurable branching unit (BU), wherein the BU enables bidirectional transmission between any two terminals, and the input signal is demultiplexed into at least one individual waveband or wavelength using at least one demultiplexer. Each demultiplexed waveband is passed through optical switches, with corresponding optical switches for the same demultiplexed waveband provided for transmission in the reverse direction. Independent per-waveband switching is performed using a demultiplexer-switch-multiplexer (DSM) architecture. Each demultiplexed waveband is multiplexed at each output port using at least one multiplexer to combine signals from different sources, and combined signals are transmitted to a destination terminal.

Abstract: Methods and systems for optical communication in a submarine network are provided. An input signal is received from a terminal at a reconfigurable branching unit (BU), and the input signal is split into at least two parts, with one part being associated with one or more trunk terminals and another part being associated with one or more branch terminals. Each of one or more spectrum channels are selected and individually switched to one of a plurality of paths using at least one wavelength selective switch (WSS), with the at least one WSS being configured to transmit the one or more spectrum channels to their respective target output port and to combine signals switched to a specific port into a wavelength division multiplexing (WDM) signal. Individual spectrum channels are filtered out using at least one wavelength blocker (WB).

Abstract: Provided are an optical amplifier, a control method therefor, and an optical transmission system that can use a simple technique to correct SRS tilt generated in a transmission path after a back-stage amplifier out of two amplifiers, which respectively amplify an input optical signal in a front stage and a back stage of a variable attenuator, in accordance with the number of wavelengths of the optical signal transmitted on the transmission path. A control parameter for controlling the two amplifiers and the attenuator is determined so as to correct a spectral slope caused by stimulated Raman scattering of the optical signal based on network information received from another device, and the two amplifiers and the attenuator are controlled based on the control parameter.

Abstract: An optical amplifier apparatus according to the invention is provided with a pumping light source that outputs pumping light for pumping first and second optical amplifying media. Therefore an input signal light is amplified by the first and second optical amplifying media mutually connected in series and a wavelength division multiplexing coupler that inputs the pumping light to both optical amplifying media and adopts configuration that an optical equalizer is arranged between the first and second optical amplifying media. Therefore, as pumping light passes the optical equalizer and pumps the two optical amplifying media by arranging the optical equalizer between both optical amplifying media, the optical amplifying medium after the optical equalizer amplifies, the loss of the optical equalizer is compensated and the optical amplification of high output is acquired.

Abstract: An optical amplifier apparatus according to the invention is provided with a pumping light source that outputs pumping light for pumping first and second optical amplifying media. Therefore an input signal light is amplified by the first and second optical amplifying media mutually connected in series and a wavelength division multiplexing coupler that inputs the pumping light to both optical amplifying media and adopts configuration that an optical equalizer is arranged between the first and second optical amplifying media. Therefore, as pumping light passes the optical equalizer and pumps the two optical amplifying media by arranging the optical equalizer between both optical amplifying media, the optical amplifying medium after the optical equalizer amplifies, the loss of the optical equalizer is compensated and the optical amplification of high output is acquired.