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

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

The present disclosure provides a range-finding system capable of data communication. The range-finding system includes a rangefinder for acquiring ranging data, a magnetic ring unit having at least two communication channels, and a data processing and control unit. Each communication channel includes a magnetic ring. The magnetic ring unit transmits the ranging data as downlink data from the rangefinder to the data processing and control unit via one or more of the communication channels.

An OAM multiplexing communication system uses one or more OAM modes and multiplexes signals of one or more sequences for each OAM mode. A transmitting station includes a transmitting antenna using an M-UCA, and an OAM mode generation unit that simultaneously generates one or more OAM modes from each UCA. A receiving station includes a receiving antenna equivalent to the M-UCA, an OAM mode separation unit that separates signals received by each UCA for each OAM mode, and a received signal processing unit that estimates channel information for each OAM mode and performs an equalization process for each OAM mode by using a receiving weight calculated from the channel information. The received signal processing unit is configured to estimate, for each OAM mode, channel information of another OAM mode causing interference and calculate the receiving weight of a subject OAM mode by using the channel information of the subject OAM mode and said another OAM mode.

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.

An optical wireless power transfer system includes a transmission module, which includes a main light source configured to output a main light; a transmitting processor configured to modulate the main light to have a first modulation; a beam splitter configured to pass the main light as a power light; and a reception module. The reception module includes a retro-reflector configured to retro-reflect the main light back to the transmission module; and a receiving processor configured to control the retro-reflector to reflect the main light to have a second modulation based on a power generated by the main light. Further, the beam splitter is further configured to reflect the main light having the second modulation to a first photodiode included in the transmission module.

An optical antenna may permit a duplex link formed by a transmit, Tx, beam towards a partner optical antenna and a receive, Rx, beam from the partner antenna. The antenna includes: a proximal path including a bidirectional waveguide for duplex propagation of the duplex link from a Tx source of the Tx beam and towards a receiver of the Rx beam; a distal path for a duplex propagation of the duplex link from/towards the partner optical antenna; a beam shaper positioned in the distal path to shape a duplex propagation pattern of the duplex link; and a controller controlling the beam shaper to adaptively shape the propagation pattern to enclose: a first position of the partner antenna at the transmission of the Rx beam; and a second of the partner antenna at the reception of the Tx beam.

A laser communication architecture provides precise optical alignment between terminals without requiring dedicated beacon lasers or dedicated beacon wavelength optics. Instead, the same lasers and optics are used for both alignment and communication. A beacon modulation is applied to alignment beacons transmitted at or near communication wavelengths so as to differentiate them from communication beams. The beacon modulation can include phase and/or amplitude variation of a high frequency modulation, and/or ping-pong toggling of the beacon wavelength. In some full duplex red/blue embodiments, ping-pong modulation is implemented by alternated red/blue tuning of the transmit laser or by switching between separate red and blue transmit lasers, for example using a 21 laser switch, while maintaining constant beacon amplitude, thereby avoiding optical amplifier dynamic response issues. During communication, embodiments maintain optical alignment by diverting a percentage of received communication light to the tracking sensor.

A wireless optical communication apparatus for performing bi-directional optical transmission in a free space includes a first optical system configured to transmit data through a downlink scheme and a second optical system configured to receive the data from the first optical system and transmit a control signal to the first optical system through an uplink scheme, wherein each of the first optical system and the second optical system transmits and receives the data and the control signal through a single port.

The present disclosure provides a range-finding system capable of data communication. The range-finding system includes a rangefinder for acquiring ranging data, a magnetic ring unit having at least two communication channels, and a data processing and control unit. Each communication channel includes a magnetic ring. The magnetic ring unit transmits the ranging data as downlink data from the rangefinder to the data processing and control unit via one or more of the communication channels.