Abstract: The technology is generally directed to a method of mapping fiber networks. The fiber networks may include a plurality of cables, such as fiber optic cables. The cable may be divided into segments. Each cable has a first end segment and a second end segment, each with a known location. When there is a perturbation that causes the cable to vibrate, each segment of the cable may experience an associated strain at a different time. Based on the known location of the perturbation sources, the known location of the end segments, and the relative time that the perturbation is detected at each cable segment, the location of each segment and, therefore, the entire cable may be determined.

Abstract: Systems and methods are provided for generating a model for detection of seismic events. In this regard, one or more processors may receive from one or more stations located along an underwater optical route, one or more time series of polarization states of a detected light signal during a time period. The one or more processors may transform the one or more time series of polarization states into one or more spectrums in a frequency domain. Seismic activity data for the time period may be received by the one or more processors, where the seismic activity data include one or more seismic events detected in a region at least partially overlapping the underwater optical route. The one or more processors then generate a model for detecting seismic events based on the one or more spectrums and the seismic activity data.

Abstract: Systems and methods are provided for generating a model for detection of seismic events. In this regard, one or more processors may receive from one or more stations located along an underwater optical route, one or more time series of polarization states of a detected light signal during a time period. The one or more processors may transform the one or more time series of polarization states into one or more spectrums in a frequency domain. Seismic activity data for the time period may be received by the one or more processors, where the seismic activity data include one or more seismic events detected in a region at least partially overlapping the underwater optical route. The one or more processors then generate a model for detecting seismic events based on the one or more spectrums and the seismic activity data.

Abstract: Systems and methods for detecting a mechanical disturbance are disclosed. One of the method may comprise the operation steps including: transmitting, by a transmitter, a pulse at a preset frequency along a first cable; receiving, by a receiver, a plurality of signals, wherein each of the plurality of signals travels along the first cable and a second cable connected to the receiver for a corresponding span; calculating one or more differential phases, wherein each differential phase is calculated based on respective phases and the corresponding spans of two of the plurality of signals; and determining a localization of the mechanical disturbance based on the one or more differential phases.

Abstract: Systems and methods are provided for generating a model for detection of seismic events. In this regard, one or more processors may receive from one or more stations located along an underwater optical route, one or more time series of polarization states of a detected light signal during a time period. The one or more processors may transform the one or more time series of polarization states into one or more spectrums in a frequency domain. Seismic activity data for the time period may be received by the one or more processors, where the seismic activity data include one or more seismic events detected in a region at least partially overlapping the underwater optical route. The one or more processors then generate a model for detecting seismic events based on the one or more spectrums and the seismic activity data.

Abstract: Systems and methods are provided for generating a model for detection of seismic events. In this regard, one or more processors may receive from one or more stations located along an underwater optical route, one or more time series of polarization states of a detected light signal during a time period. The one or more processors may transform the one or more time series of polarization states into one or more spectrums in a frequency domain. Seismic activity data for the time period may be received by the one or more processors, where the seismic activity data include one or more seismic events detected in a region at least partially overlapping the underwater optical route. The one or more processors then generate a model for detecting seismic events based on the one or more spectrums and the seismic activity data.

Abstract: Systems and methods are provided for generating a model for detection of seismic events. In this regard, one or more processors may receive from one or more stations located along an underwater optical route, one or more time series of polarization states of a detected light signal during a time period. The one or more processors may transform the one or more time series of polarization states into one or more spectrums in a frequency domain. Seismic activity data for the time period may be received by the one or more processors, where the seismic activity data include one or more seismic events detected in a region at least partially overlapping the underwater optical route. The one or more processors then generate a model for detecting seismic events based on the one or more spectrums and the seismic activity data.

Abstract: Systems and methods of undersea optical communication are provided. An undersea optical amplifier assembly can include a water-tight housing and a photonic integrated circuit disposed within the housing. The photonic integrated circuit includes a plurality of optical fiber inputs, each configured to receive an end of a respective optical fiber of a first fiber optic cable bundle, and a plurality of optical fiber outputs. Each optical fiber output corresponds to a respective optical fiber input to form a fiber optic input-output pair, and is configured to receive an end of a respective optical fiber of a second fiber optic cable bundle. The photonic integrated circuit includes an optical amplifier optically coupled to each respective fiber optic input-output pair. The housing includes a first water-tight access port configured to receive the first fiber optic cable bundle, and a second water-tight access port configured to receive a second fiber optic cable bundle.

Abstract: Systems and methods of undersea optical communication are provided. An undersea optical amplifier assembly can include a water-tight housing and a photonic integrated circuit disposed within the housing. The photonic integrated circuit includes a plurality of optical fiber inputs, each configured to receive an end of a respective optical fiber of a first fiber optic cable bundle, and a plurality of optical fiber outputs. Each optical fiber output corresponds to a respective optical fiber input to form a fiber optic input-output pair, and is configured to receive an end of a respective optical fiber of a second fiber optic cable bundle. The photonic integrated circuit includes an optical amplifier optically coupled to each respective fiber optic input-output pair. The housing includes a first water-tight access port configured to receive the first fiber optic cable bundle, and a second water-tight access port configured to receive a second fiber optic cable bundle.

Abstract: A method for overlapping spectrum amplification includes receiving an optical signal and splitting the optical signal into a first split signal having a first wavelength band and a second split signal having a second wavelength band. The splitting results in a band gap between the first wavelength band and the second wavelength band. The method further includes delaying the first split signal by a threshold period of time relative to the second split signal and combining the first split signal and the second split signal, resulting in a combined signal having the first wavelength band and the second wavelength band without the band gap therebetween. The path difference between the first split signal along the first signal path and the second split signal along the second signal path is within a threshold multipath interference compensation range.

Abstract: A method for overlapping spectrum amplification includes receiving an optical signal and splitting the optical signal into a first split signal having a first wavelength band and a second split signal having a second wavelength band. The splitting results in a band gap between the first wavelength band and the second wavelength band. The method further includes delaying the first split signal by a threshold period of time relative to the second split signal and combining the first split signal and the second split signal, resulting in a combined signal having the first wavelength band and the second wavelength band without the band gap therebetween. The path difference between the first split signal along the first signal path and the second split signal along the second signal path is within a threshold multipath interference compensation range.

Abstract: A branching unit for an optical system includes an optical add-drop multiplexer, which includes first and second filters. The first filter is configured to filter a first band of wavelengths of a communication spectrum for a first communication segment. The second filter is configured to filter a second band of wavelengths of the communication spectrum for a second communication segment. The second band of wavelengths overlaps the first band of wavelengths in an overlap band of wavelengths with no guard band between the first band of wavelengths and the second band of wavelengths. Moreover, the overlap band of wavelengths has a variable size. The first band of wavelengths includes a first fraction of the overlap band of wavelengths for the first communication segment and the second band of wavelengths includes a remaining fraction of the overlap band of wavelengths for the second communication segment.

Abstract: A communication system includes a first and second trunk terminals, a plurality of communication trunks disposed along a floor of a body of water, and power feed equipment. Each communication trunk couples the first trunk terminal to the second trunk terminal and includes at least one signal amplifier configured to amplify a signal conveyed along the corresponding communication trunk. The power feed equipment is coupled to the plurality of communication trunks and is configured to deliver power along each communication trunk to power the at least one signal amplifier of the communication trunk. The power feed equipment is also configured to receive a shunt fault notification identifying an electrical shunt fault along a faulted communication trunk of the plurality of communication trunks. In response to the shunt fault notification, the power feed equipment is configured to cease delivery of power along at least one communication trunk.

Abstract: A branching unit for an optical system includes an optical add-drop multiplexer, which includes first and second filters. The first filter is configured to filter a first band of wavelengths of a communication spectrum for a first communication segment. The second filter is configured to filter a second band of wavelengths of the communication spectrum for a second communication segment. The second band of wavelengths overlaps the first band of wavelengths in an overlap band of wavelengths with no guard band between the first band of wavelengths and the second band of wavelengths. Moreover, the overlap band of wavelengths has a variable size. The first band of wavelengths includes a first fraction of the overlap band of wavelengths for the first communication segment and the second band of wavelengths includes a remaining fraction of the overlap band of wavelengths for the second communication segment.

Abstract: An optical system for a locally powered optical communication network includes a first trunk terminal emitting an optical signal, a second trunk terminal receiving the optical signal, a communication trunk, an intermediate unit and a power source. The communication trunk is disposed along a floor of a body of water and couples the first trunk terminal to the second trunk terminal. The communication trunk transmits the optical signal from the first trunk terminal to the second trunk terminal. The intermediate unit is connected to the communication trunk between the first and second trunk terminals. The intermediate unit receives the emitted optical signal from the first trunk terminal, amplifies the received optical signal and sends the amplified optical signal to the second trunk. The power source is connected to and powers the intermediate unit and is located at or near a surface of the body of water.

Abstract: An optical system for a locally powered optical communication network includes a first trunk terminal emitting an optical signal, a second trunk terminal receiving the optical signal, a communication trunk, an intermediate unit and a power source. The communication trunk is disposed along a floor of a body of water and couples the first trunk terminal to the second trunk terminal. The communication trunk transmits the optical signal from the first trunk terminal to the second trunk terminal. The intermediate unit is connected to the communication trunk between the first and second trunk terminals. The intermediate unit receives the emitted optical signal from the first trunk terminal, amplifies the received optical signal and sends the amplified optical signal to the second trunk. The power source is connected to and powers the intermediate unit and is located at or near a surface of the body of water.

Abstract: An optical add-drop multiplexer including a first filter filtering a first band of wavelengths of a communication spectrum for a first communication and a second filter filtering a second band of wavelengths of the communication spectrum for a second communication. The second band of wavelengths overlaps the first band of wavelengths in an overlap band of wavelengths. The first band of wavelengths includes a first fraction of the overlap band of wavelengths for the first communication and the second band of wavelengths includes a remaining fraction the overlap band of wavelengths for the second communication.

Abstract: An optical add-drop multiplexer including a first filter filtering a first band of wavelengths of a communication spectrum for a first communication segment and a second filter filtering a second band of wavelengths of the communication spectrum for a second communication segment. The second band of wavelengths overlaps the first band of wavelengths in an overlap band of wavelengths. The overlap band may have a variable size. The first band of wavelengths includes a first fraction of the overlap band of wavelengths for the first communication segment and the second band of wavelengths includes a remaining fraction the overlap band of wavelengths for the second communication segment.

Abstract: An optical add-drop multiplexer including a first filter filtering a first band of wavelengths of a communication spectrum for a first communication and a second filter filtering a second band of wavelengths of the communication spectrum for a second communication. The second band of wavelengths overlaps the first band of wavelengths in an overlap band of wavelengths. The first band of wavelengths includes a first fraction of the overlap band of wavelengths for the first communication and the second band of wavelengths includes a remaining fraction the overlap band of wavelengths for the second communication.

Abstract: An optical add-drop multiplexer including a first filter filtering a first band of wavelengths of a communication spectrum for a first communication segment and a second filter filtering a second band of wavelengths of the communication spectrum for a second communication segment. The second band of wavelengths overlaps the first band of wavelengths in an overlap band of wavelengths. The overlap band may have a variable size. The first band of wavelengths includes a first fraction of the overlap band of wavelengths for the first communication segment and the second band of wavelengths includes a remaining fraction the overlap band of wavelengths for the second communication segment.