Methods, systems, and devices for network communications to reduce optical beat interference (OBI) in upstream communications are described. For example, a fiber node may provide a narrow band seed source to injection lock upstream laser diodes. Therefore, upstream communications from each injection locked laser diode may primarily include the wavelength associated with each seed source. The seed sources may be unique to each end device and configured to minimize OBI. That is, the upstream laser diodes may be generic, but the received seed source may enable upstream communications at varying wavelengths. The fiber node may provide each seed source by filtering (e.g., by a grating filter) a broadband light source.

Methods, systems, and devices for network communications to reduce optical beat interference (OBI) in upstream communications are described. For example, a fiber node may provide a narrow band seed source to injection lock upstream laser diodes. Therefore, upstream communications from each injection locked laser diode may primarily include the wavelength associated with each seed source. The seed sources may be unique to each end device and configured to minimize OBI. That is, the upstream laser diodes may be generic, but the received seed source may enable upstream communications at varying wavelengths. The fiber node may provide each seed source by filtering (e.g., by a grating filter) a broadband light source.

Disclosed herein are methods, structures, and devices for optical communications systems operating through turbulent media. More specifically, a spatial division multiplexing photonic integrated circuit is used in conjunction with digital signal processing systems to mitigate the effects of the turbulent media.

Disclosed herein are methods, structures, and devices for optical communications systems operating through turbulent media. More specifically, a spatial division multiplexing photonic integrated circuit is used in conjunction with digital signal processing systems to mitigate the effects of the turbulent media.

A mode converter provided in the present invention includes an input multimode waveguide, an output multimode waveguide, and a first conversion waveguide, where the input multimode waveguide is configured to receive a first signal which mode is a first mode; the first conversion waveguide has an input coupling waveguide with a first effective refractive index, and has an output coupling waveguide with a second effective refractive index: the first conversion waveguide is configured to perform, by using the input coupling waveguide, evanescent wave coupling on the first signal that is in the first mode and that is transmitted in the input multimode waveguide, and couple the first signal to the second mode of the output multimode waveguide by using the output coupling waveguide, so as to obtain the first signal in the second mode; and the output multimode waveguide is configured to output the first signal in the second mode.

The present disclosure provides a data transmission method including: receiving a first-mode optical signal from a first port corresponding to a first port number; converting, according to a correspondence between the first port number and a first mode group number, the received first-mode optical signal into a second-mode optical signal carried in a first mode group identified by the first mode group number, where the second-mode optical signal carried in the first mode group identified by the first mode group number includes an optical signal in one or more modes; and outputting the second-mode optical signal obtained by means of conversion.

The present disclosure provides a data transmission method including: receiving a first-mode optical signal from a first port corresponding to a first port number; converting, according to a correspondence between the first port number and a first mode group number, the received first-mode optical signal into a second-mode optical signal carried in a first mode group identified by the first mode group number, where the second-mode optical signal carried in the first mode group identified by the first mode group number includes an optical signal in one or more modes; and outputting the second-mode optical signal obtained by means of conversion.

The present disclosure discloses a data transmission method, an apparatus, and a system. The method includes: receiving, by a mode multiplexer from an input port, a first optical signal transmitted by an optical line terminal; converting, according to a correspondence between an input port of an optical signal and a mode of the optical signal, the received first optical signal into a second optical signal in a mode corresponding to the input port; and multiplexing the second optical signal obtained by means of conversion to a few-mode optical fiber for transmission. This increases transmission capacity of a single optical fiber and implements fast expansion of the transmission capacity, thereby improving total bandwidth utilization of a system.

The present disclosure discloses a data transmission method, an apparatus, and a system. The method includes: receiving, by a mode multiplexer from an input port, a first optical signal transmitted by an optical line terminal; converting, according to a correspondence between an input port of an optical signal and a mode of the optical signal, the received first optical signal into a second optical signal in a mode corresponding to the input port; and multiplexing the second optical signal obtained by means of conversion to a few-mode optical fiber for transmission. This increases transmission capacity of a single optical fiber and implements fast expansion of the transmission capacity, thereby improving total bandwidth utilization of a system.

In one embodiment, an optical system for processing space-multiplexed optical signals includes an input fiber that propagates multiple spatially-separated optical signals, a photonic signal processor that receives the multiple spatially-separated optical signals and simultaneously processes those signals, and an output fiber that receives at least one of the processed signals.