Disclosed is a submarine network device, comprising a fiber set, a pump laser set, an erbium doped fiber amplifier (EDFA) set, a primary fiber coupler (CPL) set and a secondary CPL set, wherein the primary CPL set comprises N primary CPLs, the secondary CPL set comprises N secondary CPLs, with N being an integer greater than or equal to 3. The fiber set is configured to connect the pump laser set, the primary CPL set, the secondary CPL set and the EDFA set. An input port of each primary CPL in the primary CPL set is at least connected with a pump laser. An output port of each secondary CPL in the secondary CPL set is at least connected with an EDFA. Output ports of each primary CPL in the primary CPL set are respectively connected with two different secondary CPLs that are spaced by a secondary CPL, and input ports of each secondary CPL in the secondary CPL set are respectively connected with two different primary CPLs that are spaced by a primary CPL.

Disclosed is a submarine network device, comprising a fiber set, a pump laser set, an erbium doped fiber amplifier (EDFA) set, a primary fiber coupler (CPL) set and a secondary CPL set, wherein the primary CPL set comprises N primary CPLs, the secondary CPL set comprises N secondary CPLs, with N being an integer greater than or equal to 3. The fiber set is configured to connect the pump laser set, the primary CPL set, the secondary CPL set and the EDFA set. An input port of each primary CPL in the primary CPL set is at least connected with a pump laser. An output port of each secondary CPL in the secondary CPL set is at least connected with an EDFA. Output ports of each primary CPL in the primary CPL set are respectively connected with two different secondary CPLs that are spaced by a secondary CPL, and input ports of each secondary CPL in the secondary CPL set are respectively connected with two different primary CPLs that are spaced by a primary CPL.

Described herein are photonic integrated circuits (PICs) comprising a semiconductor optical amplifier (SOA) to output a signal comprising a plurality of wavelengths, a sensor to detect data associated with a power value of each wavelength of the output signal of the SOA, a filter to filter power values of one or more of the wavelengths of the output signal of the SOA, and control circuitry to control the filter to reduce a difference between a pre-determined power value of each filtered wavelength of the output signal of the SOA and the detected power value of each filtered wavelength of the output signal of the SOA.

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.

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.

An optical amplifier includes an input port for receiving an input optical signal; a wavelength division multiplexer (204) having a first input coupled to the input port, a second input coupled to a pump source (206), and an output coupled to an amplification fiber (208); and an integrated component (210) configured to provide output monitoring and isolation, wherein the integrated component (210) is configured to separate a first portion of a light signal received from the amplification fiber (208), direct the first portion to a photo detector, direct a second portion of the input light from the amplification fiber (208) to an output port, and attenuate light signals received from the output port.

An optical amplifier includes an input port for receiving an input optical signal; a wavelength division multiplexer (204) having a first input coupled to the input port, a second input coupled to a pump source (206), and an output coupled to an amplification fiber (208); and an integrated component (210) configured to provide output monitoring and isolation, wherein the integrated component (210) is configured to separate a first portion of a light signal received from the amplification fiber (208), direct the first portion to a photo detector, direct a second portion of the input light from the amplification fiber (208) to an output port, and attenuate light signals received from the output port.

Disclosed are devices, systems, apparatuses, methods, products, and other implementations of GNSS repeater systems and methods for improving phase and frequency alignment of RF signals transported through fiber optic communication channels. Acquired RF signals are processed at a remote outdoor unit, where they are digitized, formatted into a CPRI frame, and timestamped. The timestamped CPRI frame is then transported over a fiber optic communication channel to an indoor head end unit. The indoor head end unit extracts timestamp and digitized RF signal from the CPRI frame. The timestamp is then used to synchronize a base transceiver station (BTS) and a precision time protocol (PTP) grand master with the remote outdoor unit.

Disclosed are devices, systems, apparatuses, methods, products, and other implementations of GNSS repeater systems and methods for improving phase and frequency alignment of RF signals transported through fiber optic communication channels. Acquired RF signals are processed at a remote outdoor unit, where they are digitized, formatted into a CPRI frame, and timestamped. The timestamped CPRI frame is then transported over a fiber optic communication channel to an indoor head end unit. The indoor head end unit extracts timestamp and digitized RF signal from the CPRI frame. The timestamp is then used to synchronize a base transceiver station (BTS) and a precision time protocol (PTP) grand master with the remote outdoor unit.

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.