A method of free-space optical communication includes guiding, by focusing optics, an optical communication beam emitted from an optical transmitter into a double-clad optical fiber. The optical communication beam carrying data. The double-clad optical fiber has first and second ends, where the first end is arranged to receive the optical communication beam. The double-clad optical fiber includes a fiber core, a first cladding, and a second cladding. The method also includes directing, by collimating optics, the optical communication beam from the second end of the double-clad optical fiber toward an optical receiver of a communication terminal. the second portion of the optical communication beam arranged concentrically around the first portion of the optical communication beam, the first portion of the optical communication beam having a higher intensity than the second portion of the optical communication beam.

A radio communication system for duplex communication comprising an optical carrier generator for generating optical carrier signals, a local oscillator (LO) for generating an electrical signal in a radio communication band, an information signal source, electro-optic modulators driven directly at an input electrical port by said information signal and said LO signal to modulate a portion of said optical carrier signal to form a modulated portion being an optical band information signal for transmission over an optical link; and a photodetector remote from said electro-optic modulators for receiving said transmitted optical band information signal from said optical link, and directly generating an electrical signal that is up-converted for radio transmission, or down-converted to a baseband frequency.

A spatial optical transmitter modulates an optical signal of a single wavelength in accordance with a signal to be transmitted, divides the modulated optical signal into two, rotates polarizations of the two divided optical signals, and transmits the two optical signals as optical signals of two orthogonal polarizations to space.

Methods, devices, and systems are described for free space optical communication. An example device can comprise a defocuser configured to receive an optical signal from a laser and control a beam divergence of the optical signal. The optical signal can comprise a data signal and a beacon signal. The device can comprise a controller configured to cause the defocuser to adjust the beam divergence based on an operational mode of the laser.

An optical transmission system includes a first optical communication device configured to output an optical signal, a first FBG-DCM configured to perform wavelength dispersion compensation on the optical signal output by the first optical communication device, and a second optical communication device configured to receive the optical signal wavelength-dispersion compensated by the first FBG-DCM through at first optical transmission path of an optical fiber.

A satellite includes a plurality of transceivers, each configured to selectively connect to one of another transceiver in another satellite and a ground station; and configurable pass-through between the plurality of transceivers that is configured based on a location of the satellite in a constellation. The configurable pass-through can provide data signal pass-through without one or more of full decoding, regeneration, and error correction, thereby saving power.

Systems and methods for performing operations based on LIDAR communications are described. An example device may include one or more processors and a memory coupled to the one or more processors. The memory includes instructions that, when executed by the one or more processors, cause the device to receive data associated with a modulated optical signal emitted by a transmitter of a first LIDAR device and received by a receiver of a second LIDAR device coupled to a vehicle and the device, generate a rendering of an environment of the vehicle based on information from one or more LIDAR devices coupled to the vehicle, and update the rendering based on the received data. Updating the rendering includes updating an object rendering of an object in the environment of the vehicle. The instructions further cause the device to provide the updated rendering for display on a display coupled to the vehicle.

There includes: an optical splitter splitting modulated light into local oscillator light and signal light beams; a phase adjustment unit adjusting phases of signal light beams; an optical amplification unit amplifying signal light beams phase-adjusted; an optical phased array antenna outputting signal light beams amplified to space; a phase control unit synchronizing with a reference signal light beams, output from the optical phased array antenna and multiplexed with the local oscillator light; an acquisition and tracking mechanism adjusting output angles of signal light beams; an angle detection unit detecting arrival angles of received light; and a control unit setting the reference signal to first reference signals having different frequencies, supplementing the received light based on a detection result, setting the reference signal to second reference signals having equal frequencies, and tracking the received light based on the detection result.

A communication device includes an interleaving unit that determines an interleaving length of transmit data to be transmitted through free-space optical communication, and interleaves the transmit data based on the determined interleaving length, and a shaping unit that shapes the interleaved transmit data so as to make the interleaving length detectable on a receiving side of the free-space optical communication.

An optical communication system using a photonic lantern for fine point tracking is disclosed. The optical communication system may comprise a photonic lantern, a signal processing unit including one or more fiber splitters to sample a fraction of a received signal in each single mode fiber of the photonic lantern, and one or more intensity sensors positioned in one arm of each fiber splitter, and used for monitoring fiber-specific intensity data associated with each of the single-mode fibers. The system may further include a fine pointing assembly and a controller for controlling a driver of the fine pointing assembly.