An underwater wireless optical communication, UWOC, unit (30) for underwater deployment on a submerged earth layer (12) or structure (14, 16). The UWOC unit is configured for wireless optical communication in an underwater environment, and comprises an optical transmitter (36), an anidolic optical receiver (38), and a processor (44). The optical transmitter is configured to transmit data by emitting an optical signal (80) into the surroundings. The optical receiver includes an optical detector (62), which is omnidirectionally sensitive and configured to receive further optical signals approaching substantially along an azimuthal plane orthogonal to a nominal axis (A) through the UWOC unit. The processor is coupled to the optical receiver, and configured to process received further optical signals. The unit may be configured to determine an inter-unit distance between this unit and a second unit, by sending an optical interrogation signal to the second unit, and receiving an optical response signal from the second unit.

A method of coordinating wireless power transfer and data communication between a transmitter and a receiver comprising recognizing at the receiver that an energy store electrically coupled to the receiver requires an electrical charge, emitting from the receiver a beacon signal to the transmitter, the beacon signal including information about the receiver and a state of charge of the energy store, recognizing at the receiver first and second localization signals from the transmitter, establishing low-power and high-power laser beam connections between the receiver and the transmitter in response to the localization signals, and communicating further information via the low-power beam on a periodic basis while optical power is being transferred via the high-power beam. The low-power beam connection includes further information about the receiver and the state of charge of the energy store. Optical power is transferred from the transmitter to the receiver via the high-power beam.

Techniques are disclosed for aligning an optical transmitter with an optical receiver for a line-of-sight communications link, wherein the optical transmitter comprises a laser array emitter, the laser array emitter comprising a plurality of laser emitting regions, wherein each of a plurality of the laser emitting regions is configured to emit laser light in a different direction such that the laser array emitter is capable of emitting laser light in a plurality of different directions. The system can run produce emissions from different laser emitting regions until a laser emitting region that is in alignment with the optical receiver is found. This aligned laser emitting region can then be selected for use to optically communicate data from the optical transmitter to the optical receiver.

An optical transmission/reception unit includes a carrier rotatable about a rotational axis, an optical receiver arranged at the carrier on the rotational axis to receive an optical reception signal from a first direction, an optical transmitter arranged adjacent to the optical receiver at the carrier to emit an optical transmission signal in a second direction, and a transmission/reception optic arranged at the carrier on the rotational axis above the optical receiver and extending across the optical receiver and the optical transmitter, wherein the transmission/reception optic includes a reception optic and a transmission optic arranged in the reception optic. The reception optic is configured to guide the optical reception signal incident on the transmission/reception optic towards the optical receiver on the rotational axis, and the transmission optic is arranged above the optical transmitter and is configured to shape the optical transmission signal emitted by the optical transmitter into an output beam.

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 device can comprise a controller configured to cause the defocuser to adjust the beam divergence based on an operational mode of the laser.

Embodiments are directed to systems and methods for providing light communication (LC) for an aircraft. An LC transmitter is mounted on an aircraft fuselage and is configured to broadcast light signals within a defined region outside the aircraft. An LC receiver mounted on the aircraft fuselage is configured to receive light signals broadcast by a remote LC device. A controller is configured to manage LC signals in the aircraft, and an interface is provided between the controller and an aircraft data network. The light signals may be in a visible light spectrum, an invisible light spectrum, or both. The remote LC device may be, for example, a ground station, an aircraft, a ground vehicle, a ship, a building, or a portable transmitter.

The purpose of the present invention is to provide an optical/RF wireless hybrid communication system and a control method capable of solving the instability of link conditions of an RF wireless link and an optical wireless link. In the optical/RF wireless hybrid communication system and the control method according to the present invention, links for data transmission are not limited to one of an RF wireless link and an optical wireless link, the quality of link conditions is determined from signal quality received through channels of both the RF wireless link and the optical wireless link, and the distribution of data to be transmitted through the respective links is determined on the basis of the determination result. Thus, the links can be flexibly switched depending on the transmission conditions such as disturbance.

This application relates to the field of space communications technologies, and provides an acquisition, pointing, and tracking (APT) subsystem and a spacecraft communications system. The APT subsystem includes a first controller, a first terahertz transceiver, and a terahertz antenna array that are sequentially connected, where the first terahertz transceiver is configured to modulate and demodulate a terahertz wave; the terahertz antenna array is configured to send and receive the terahertz wave; and the first controller is configured to control the first terahertz transceiver to acquire, point, and track another APT subsystem by using the terahertz antenna array.

The disclosure describes a system that includes a self-driving system for operating a vehicle autonomously, one or more optical transmitters mounted on the vehicle, and one or more computing devices in communication with the self-driving system and the one or more optical transmitters. The one or more computing devices are configured to operate the self-driving system to cause the vehicle to approach a designated location in proximity of a structure on which one or more receivers are mounted and determine that the one or more optical transmitters have an alignment with the one or more receivers. Then, the one or more computing devices are configured to operate the one or more optical transmitters to establish an optical communication link with the one or more receivers and transmit data to the one or more receivers over the optical communication link.

An optical communications system including two communications terminals in communication with each other using optical signals having the same wavelength. Both terminals include a half-wave plate polarizer for rotating linearly polarized optical signals and a quarter-wave plate polarizer for circularly polarizing the optical signals. The quarter-wave plate polarizers are oriented 90° relative to each other so that circularly polarized optical signals sent from one terminal to the other terminal are linearly polarized 90° relative to a transmission polarization orientation to be separable from the transmitted optical signals by a beam splitter.