Systems and methods are provided for creating a sequence of turn-up processes for amplifiers. A method, according to one implementation, includes determining when a fiber span is initially installed in an optical line system or when an Optical Line Failure (OLF) in the fiber span has recovered. The optical line system includes a first set of amplifiers deployed at an upstream node and a second set of amplifiers deployed at a downstream node, the upstream node connected to the downstream node via the fiber span. In response to determining that the fiber span is initially installed in the optical line system or that an ORL in the fiber span has recovered, the method also includes sending a flag from the upstream node to the downstream node to allow the first set of amplifiers to perform a first turn-up process before the second set of amplifiers perform a second turn-up process.

Provided herein are hybrid optical/acoustic wireless communications platforms for aquatic environments, the platforms comprising: an optical communications system configured to send and receive optical communications signals along a bed of the aquatic environment; an optical/acoustic communications signal converter; and an acoustic communications system configured to send and receive acoustic communications signals between the bed of the aquatic environment and a surface of the aquatic environment.

Provided herein are hybrid optical/acoustic wireless communications platforms for aquatic environments, the platforms comprising: an optical communications system configured to send and receive optical communications signals along a bed of the aquatic environment; an optical/acoustic communications signal converter; and an acoustic communications system configured to send and receive acoustic communications signals between the bed of the aquatic environment and a surface of the aquatic environment.

Aspects of the subject disclosure may include, for example, a node device includes an interface configured to receive first signals. A plurality of coupling devices are configured to launch the first signals on a transmission medium as a plurality of first guided electromagnetic waves at corresponding plurality of non-optical carrier frequencies, wherein the plurality of first guided electromagnetic waves are bound to a physical structure of the transmission medium. Other embodiments are disclosed.

Aspects of the subject disclosure may include, for example, a node device includes an interface configured to receive first signals. A plurality of coupling devices are configured to launch the first signals on a transmission medium as a plurality of first guided electromagnetic waves at corresponding plurality of non-optical carrier frequencies, wherein the plurality of first guided electromagnetic waves are bound to a physical structure of the transmission medium. Other embodiments are disclosed.

A method of manufacturing a doped polycrystalline ceramic optical device includes mixing a plurality of transition metal complexes and a plurality of rare-earth metal complexes to form a metal salt solution, heating the metal salt solution to form a heated metal salt solution, mixing the heated metal salt solution and an organic precursor to induce a chemical reaction between the heated metal salt solution and the organic precursor to produce a plurality of rare-earth doped crystalline nanoparticles, and sintering the plurality of rare-earth doped nanoparticles to form a doped polycrystalline ceramic optical device having a rare-earth element dopant that is uniformly distributed within a crystal lattice of the doped polycrystalline ceramic optical device.

A method of manufacturing a doped polycrystalline ceramic optical device includes mixing a plurality of transition metal complexes and a plurality of rare-earth metal complexes to form a metal salt solution, heating the metal salt solution to form a heated metal salt solution, mixing the heated metal salt solution and an organic precursor to induce a chemical reaction between the heated metal salt solution and the organic precursor to produce a plurality of rare-earth doped crystalline nanoparticles, and sintering the plurality of rare-earth doped nanoparticles to form a doped polycrystalline ceramic optical device having a rare-earth element dopant that is uniformly distributed within a crystal lattice of the doped polycrystalline ceramic optical device.

An object to provide a submarine optical transmission apparatus capable of efficiently housing optical components and electric components. First component housing units can house either or both of an optical component and an electric component and are stacked in a Z-direction. A case can house the first component housing units and a longitudinal direction thereof is an X-direction. A heat dissipating member is disposed in the case and conducts heat generated in the first component housing units to the case.

A method and an apparatus for satellite laser broadband demodulation are provided. The method includes: setting a residual carrier to a carrier acquisition range of a receiver, pulling the residual carrier to an MHz level by adjusting a frequency of a local oscillator laser, and obtaining a precise carrier frequency according to an accurate frequency acquisition, such that the residual carrier enters a fast acquisition band of a carrier tracking phase-locked loop. After carrier acquisition is achieved, carrier tracking and data recovery processing are performed. According to the present disclosure, signal equalization of an ultra-high bandwidth/ultra-high bit rate can be implemented, and carrier acquisition, tracking, and demodulation are quickly achieved for a modulation signal in a high dynamic range.

A method and an apparatus for satellite laser broadband demodulation are provided. The method includes: setting a residual carrier to a carrier acquisition range of a receiver, pulling the residual carrier to an MHz level by adjusting a frequency of a local oscillator laser, and obtaining a precise carrier frequency according to an accurate frequency acquisition, such that the residual carrier enters a fast acquisition band of a carrier tracking phase-locked loop. After carrier acquisition is achieved, carrier tracking and data recovery processing are performed. According to the present disclosure, signal equalization of an ultra-high bandwidth/ultra-high bit rate can be implemented, and carrier acquisition, tracking, and demodulation are quickly achieved for a modulation signal in a high dynamic range.