A free-space optical communication method is provided. The method includes generating, at a transmitter of a satellite, an optical frequency comb and a pump signal, modulating the optical frequency comb to generate a data signal and an idler signal that is a phase conjugate of the data signal, attenuating the pump signal, transmitting over free-space, from the satellite, a communication signal having the data signal, the idler signal and the pump signal, receiving from the satellite, at a receiver, the transmitted communication signal having the data signal, the idler signal, and the attenuated pump signal, amplifying, at a phase-sensitive amplifier, the data signal and the idler signal, and demodulating the data signal and the idler signal to extract data.

Aspects of the disclosure provide an optical communication system. The system may include a receiver lens system configured to receive a light beam from a remote optical communication system and direct the light beam to a photodetector. The system may also include the photodetector. The photodetector may be configured to convert the received light beam into an electrical signal, and the photodetector may be positioned at a focal plane of the receiver lens system. The system may also include a phase-aberrating element arranged with respect to the receiver lens system and the photodetector such that the phase-aberrating element is configured to provide uniform angular irradiance at the focal plane of the receiver lens system.

A free-space optical communication method is provided. An example method may include generating an optical frequency comb comprising a first tone and a second tone different from the first tone. The method may include modulating, by a first modulator of a first device, the first tone to generate a first signal comprising data. The method may include modulating, by a second modulator of the first device, the second tone to generate a second signal that is a phase conjugate of the first signal. The method may include transmitting, via free-space and to a second device, a communication signal having the first signal and the second signal.

A mobile device includes an image sensor separated from a processing component by an open space. The image sensor includes one or more light source modules and the processing component includes one or more light sensors aligned with the one or more light source modules. Image data from the image sensor may be transmitted to the processing component via light signals exchanged between the one or more light source modules and the one or more light sensors. In some embodiments, light signals transmitted between one or more light source modules of an image sensor and one or more light sensors of the processing component are used to determine positional and angular data about the image sensor.

Aspects of the disclosure provide an optical communication system. The system may include a receiver lens system configured to receive a light beam from a remote optical communication system and direct the light beam to a photodetector. The system may also include the photodetector. The photodetector may be configured to convert the received light beam into an electrical signal, and the photodetector may be positioned at a focal plane of the receiver lens system. The system may also include a phase-aberrating element arranged with respect to the receiver lens system and the photodetector such that the phase-aberrating element is configured to provide uniform angular irradiance at the focal plane of the receiver lens system.

Aspects of the disclosure provide an optical communication system. The system may include a receiver lens system configured to receive a light beam from a remote optical communication system and direct the light beam to a photodetector. The system may also include the photodetector. The photodetector may be configured to convert the received light beam into an electrical signal, and the photodetector may be positioned at a focal plane of the receiver lens system. The system may also include a phase-aberrating element arranged with respect to the receiver lens system and the photodetector such that the phase-aberrating element is configured to provide uniform angular irradiance at the focal plane of the receiver lens system.

Embodiments relate to a free space optical (FSO) communication terminal. The terminal includes an optical source and optics. The optical source can produce optical beams at different wavelengths. The optics direct optical beams in a direction towards a remote FSO communication terminal. A wavelength dependence of the optics results in a divergence of the optical beam that depends on a wavelength of the optical beam. A controller may control the wavelength of the optical beam produced by the optical source, thereby adjusting the divergence of the optical beam (e.g., according to an acquisition process or a tracking process).

A system and method for performing free space optical communication with a plurality of streetlamp assemblies. The method includes transmitting a light beam from a first free space optical (FSO) unit of a first streetlamp assembly to a second FSO unit of a second streetlamp assembly along a transmission path. A transmission error is detected while transmitting the light beam along the transmission path. A location of one or more smart minors is obtained. An alternate transmission path is determined from the first FSO unit to the second FSO unit or a third FSO unit. The alternate transmission path includes a reflection of the light beam from the one or more smart minors. The first FSO unit is oriented with respect to the alternate transmission path. The light beam is transmitted from the first FSO unit along the alternate transmission path.

Aspects of the disclosure provide for a method of aligning a tracking system of a communication device. The method includes receiving an optical beam at the communication device. A first beam portion is received at the tracking system, and a second beam portion is received at an optical fiber of the communication device. Using one or more processors, an first signal and an second signal is received from the tracking system. The one or more processors are also used to determine a phase difference related to the first signal and a second phase difference related to the second signal. An offset for the first signal and an offset for the second signal are determined based on the respective phase difference. The one or more processors then track the optical beam using the tracking system and the determined offsets.

A dual-mode imaging receiver (DMIR) can acquire and maintain SOA free-space optical communication (FSOC) links without a precision mechanical gimbal. Unlike other FSOC technologies, a DMIR can operate without precise spatial alignment and calibration of the transmitter's or receiver's spatial encoders (precision pointing) in static (fixed point to point) geometries. Instead, a DMIR uses electronic receive beam selection to acquire and track transmitters with coarse mechanical pointing and a single aperture. And because the DMIR can operate with just one aperture, it does not need a beacon at the transmitter since it does not transition from a wide field-of-view acquisition aperture to a narrow field-of-view detection and decoding aperture even in dynamic geometries.