A free space optical communication system transmits and receives optical signals in a colorless manner using an optical circulator. The system installs the optical circulator with a single mode (SM) fiber at port 1, a double clad (DC) fiber at port 2, and a multimode (MM) fiber at port 3. The system injects a first optical signal into a core of the SM fiber. The system then routes the first optical signal at port 1, using the optical circulator, into a SM core of the DC fiber via Port 2. Further, the system injects a second optical signal into a first cladding of the DC fiber. The system then routes the second optical signal at port 2, using the optical circulator, into the MM fiber via Port 3.

A transmitter of a wireless power transfer and data communication system comprising a transmitter system including a transmitter housing, one or more high-power laser sources, a laser controller, one or more low-power laser sources, one or more photodiodes, a beam steering system and lens assembly, and a safety system. High-power and low-power beams are directed to corresponding receivers and transceivers of a transceiver system inside a remote receiver system by the controller and the beam steering system and lens assembly. Low-power beams include optical communication to the transceiver system. The photodiodes of the transmitter system receive optical communication from the transceiver system. Low-power beams are co-propagated with and in close proximity to high-power beams substantially along an entire distance between the transmitter housing and the receiver system. The safety system instructs the controller to reduce the high-power sources in response to detected events.

The disclosure provides for a method for reacquiring a communication link between a first communication device and a second communication device. The method includes using one or more processors of the first communication device to receive historical data related to the first communication device and an environment surrounding the first communication device. The one or more processors are then used to determine one or more trends in the historical data related to fading of the communication link. Based on the one or more trends, the one or more processors are used to determine a starting time and an initial search direction for a search for the communication link. The one or more processors then execute the search at the starting time from the initial search direction.

A controller comprises processing circuitry to collect traffic information in a geographic region and generate traffic statistics for the region using the traffic information and a communication interface to forward the traffic statistics to an optical transmitter assembly. Other examples may be described and claimed.

In the mobile communications of the fifth generation or the like, a radio relay apparatus capable of stably over a wide area realize a three-dimensional network, in which a propagation delay is low, a simultaneous connection with a large number of terminal apparatuses in a wide-range and high-speed communication can be performed, and a system capacity per unit area is large, in radio communications with terminal apparatuses including devices for the IoT, and there is no influence on radio wave frequency resources, is provided. The radio relay apparatus comprises a floating object provided with a radio relay station and controlled to be located in a floating airspace with an altitude less than or equal to 100 [km] by an autonomous control or an external control, an optical communication section for performing optical communication with an optical communication destination via an optical antenna apparatus controllable to change outgoing directional beam, an information acquisition section for acquiring at least one of optical-beam control information provided with a radio relay station and a reception sensitivity of the optical communication section, and a beam control section for controlling a directional beam of the optical antenna apparatus based on information acquired by the information acquisition section.

Systems and methods are described for providing high throughput connectivity between multiple network nodes, such as satellites in Earth orbit or ground stations, using a multi-access free space optical communications transceiver. The transceiver includes a focal plane assembly with an array of moveable optical fibers or fiber bundles, multi-core fibers, or a combination thereof. Each optical fiber bundle may include a centrally-located data fiber with guide fibers disposed around the data fiber. A controller may align a tip of the data fiber with a focal spot associated with incoming optical signals based on measured power levels of optical signals received in the guide fibers. The data fiber may be a multi-mode fiber (MMF) and circuitry in the transceiver may couple signals from the MMF into separate single-mode fibers (SMF) and then coherently combine signals from the SMFs.

A dynamic short range free-space optical (FSO) communication system that is specially designed for use in dynamically moving targets that are within a short range of distance (e.g., 0-50 meters) is provided herein. Using specially designed transmitters and/or receivers, the dynamic short range FSO communication system may facilitate high-bandwidth communication, while allowing several line of sight alignment options that may be useful for somewhat unpredictable vehicle movement.

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 device for a sending and receiving unit of a communication arrangement is provided. The device includes: a first passage for electromagnetic waves and a second passage for electromagnetic waves; a partially transparent surface which is transparent for electromagnetic waves of a first wave length range and which is reflective for electromagnetic waves of a second wave length range, wherein the second wave length range differs from the first wave length range; and a first retroreflective surface which is retroreflective for electromagnetic waves of the first wave length range. A direction of reflection of the electromagnetic waves of the first wave length range differs from a direction of reflection of the electromagnetic waves of the second wave length range if the electromagnetic waves of the first wave length range as well as the electromagnetic waves of the second wave length range are incoming through the same passage.

In the mobile communications of the fifth generation or the like, a radio relay apparatus capable of stably over a wide area realize a three-dimensional network, in which a propagation delay is low, a simultaneous connection with a large number of terminal apparatuses in a wide-range and high-speed communication can be performed, and a system capacity per unit area is large, in radio communications with terminal apparatuses including devices for the IoT, and there is no influence on radio wave frequency resources, is provided. The radio relay apparatus comprises a floating object provided with a radio relay station and controlled to be located in a floating airspace with an altitude less than or equal to 100 [km] by an autonomous control or an external control, an optical communication section for performing optical communication with an optical communication destination via an optical antenna apparatus controllable to change outgoing directional beam, an information acquisition section for acquiring at least one of optical-beam control information provided with a radio relay station and a reception sensitivity of the optical communication section, and a beam control section for controlling a directional beam of the optical antenna apparatus based on information acquired by the information acquisition section.