An optical repeater device includes an amplifier module and a monitoring control circuit. The optical amplifier module includes an amplifier optical circuit including a plurality of amplification cores that amplify signal light propagating through different cores, and an optical amplifier control circuit that receives detection results from optical detectors at a plurality of signal light waveguide points of the amplifier optical circuit and generates a control signal directed to an excitation light source. The monitoring control circuit includes a reception unit that receives monitoring control channel light, a transmission unit that transmits the monitoring control channel light, an information determination unit that determines whether the monitoring control information received from the reception unit is for its own device or for another device, and a monitoring control unit that receives monitoring control information from the other device via the reception unit and the information determination unit and transmits the monitoring control information of its own device to the other device via the transmission unit and the information determination unit.

A system and method for applying a time-varying phase shift to an optical signal is described. Such a phase shift results in a frequency shift of the optical signal, which can be useful for instance in sensing applications. The design uses cross phase modulation (XPM) in a nonlinear medium such as optical fiber. The pump producing the XPM experiences a change in energy along the medium, for instance due to loss. The pump and signal have mismatched group velocities such that they walk-off each other in time, and the pump pulse repetition rate is chosen so that it has a specific relationship with respect to the walk-off. The design is compatible with very low signal loss and does not require high fidelity electrical control signals. It is capable of high-efficiency one-directional serrodyne frequency shifts, as well as producing symmetric frequency shifts. It can also be made polarization independent.

A system and method for applying a time-varying phase shift to an optical signal is described. Such a phase shift results in a frequency shift of the optical signal, which can be useful for instance in sensing applications. The design uses cross phase modulation (XPM) in a nonlinear medium such as optical fiber. The pump producing the XPM experiences a change in energy along the medium, for instance due to loss. The pump and signal have mismatched group velocities such that they walk-off each other in time, and the pump pulse repetition rate is chosen so that it has a specific relationship with respect to the walk-off. The design is compatible with very low signal loss and does not require high fidelity electrical control signals. It is capable of high-efficiency one-directional serrodyne frequency shifts, as well as producing symmetric frequency shifts. It can also be made polarization independent.

A plastic optical fiber communication system includes a light source that emits a first signal having a first wavelength in a visible light spectrum, the first signal being encoded with information at a high data-rate of 0.1 to 10 Gbit/s; a pump laser system that emits a pump laser light having a second wavelength, different from the first wavelength; a perovskite-doped optical fiber excited by the pump laser light to generate an amplified spontaneous emission spectrum that encompasses the first wavelength so as to receive and amplify the first signal for generating an amplified output signal having the first wavelength; and a photodetector optically coupled to the perovskite-doped optical fiber, and configured to receive the amplified output signal at the high data-rate of 0.1 to 10 Gbit/s. The amplified output signal is encoded with the information.

An optical communication apparatus includes an optical switch, a wavelength management control unit, and an optical switch control unit. The optical switch is connected to a plurality of transmission lines and outputs an optical signal input from one of the transmission lines to another of the transmission lines. The wavelength management control unit assigns a wavelength to a subscriber terminal according to a communication destination. The optical switch control unit controls the optical switch such that it outputs an optical signal transmitted from the subscriber terminal, to which a wavelength has been assigned, to a transmission line corresponding to its forwarding destination on a path to the communication destination.

An optical communication apparatus includes an optical switch, a wavelength management control unit, and an optical switch control unit. The optical switch is connected to a plurality of transmission lines and outputs an optical signal input from one of the transmission lines to another of the transmission lines. The wavelength management control unit assigns a wavelength to a subscriber terminal according to a communication destination. The optical switch control unit controls the optical switch such that it outputs an optical signal transmitted from the subscriber terminal, to which a wavelength has been assigned, to a transmission line corresponding to its forwarding destination on a path to the communication destination.

Disclosed herein are methods, devices, and system for beam forming and beam steering within ultra-wideband, wireless optical communication devices and systems. According to one embodiment, a free space optical (FSO) communication apparatus is disclosed. The FSO communication apparatus includes a semiconductor optical device configured to have a transient response time of less than 500 picoseconds (ps), a lens, and a first band select filter.

This disclosure describes C and L band optical communications module link extender, and related systems and methods. An example method may include receiving, by a dense wave division multiplexer (DWDM) at a headend, one or more optical data signals over a C band and an L band. The example method may also include combining the one or more optical data signals. The example method may also include outputting a second signal to a first WDM at the headend. The example method may also include separating, by the first WDM, the second signal into a C band signal and an L band signal. The example method may also include outputting the C band signal to a first amplifier at the headend and the L band signal to a second amplifier at the headend. The example method may also include amplifying, by the first amplifier, the C band signal. The example method may also include outputting an amplified C band signal to a coexistence filter. The example method may also include amplifying, by the second amplifier, the L band signal. The example method may also include outputting an amplified L band signal to the coexistence filter. The example method may also include outputting, by the coexistence filter, a third signal.

An object is to provide an optical repeater that improves the fault tolerance of a plurality of excitation light sources while sharing the excitation light sources among a plurality of optical fibers. An optical repeater (100) includes excitation light sources (S1-S5), optical amplification units (A1-A5), and an optical distribution unit (10). The optical amplification units (A1-A5) amplify optical signals by using lights output from the excitation light sources (S1-S5). The optical distribution unit (10) includes a plurality of optical multiplexing/demultiplexing units. The optical distribution unit (10) is configured in such a manner that the lights from the four different excitation light sources in the excitation light sources (S1-S5) to be input to each of the light amplification units (A1-A5).

An object is to provide an optical repeater that improves the fault tolerance of a plurality of excitation light sources while sharing the excitation light sources among a plurality of optical fibers. An optical repeater (100) includes excitation light sources (S1-S5), optical amplification units (A1-A5), and an optical distribution unit (10). The optical amplification units (A1-A5) amplify optical signals by using lights output from the excitation light sources (S1-S5). The optical distribution unit (10) includes a plurality of optical multiplexing/demultiplexing units. The optical distribution unit (10) is configured in such a manner that the lights from the four different excitation light sources in the excitation light sources (S1-S5) to be input to each of the light amplification units (A1-A5).