Embodiments are directed towards a safety system that can be used with a high-flux power beam, such as in wireless power transmission. The system includes a transmitter that generates and transmits a power beam and a receiver that receives the power beam. A plurality of sensors is configured to independently detect if an object is near, impeding, or about to impede (i.e., impinging) the power beam. Each of the plurality of sensors is configured to detect the object at different distances between the transmitter and the receiver. A controller triggers the transmitter to stop generating the power beam when any one or more of the plurality of sensors detects the object or a combination of the plurality of sensors detects the object. The controller triggers the transmitter to re-generate and transmit the power beam when each of the plurality of sensors fails to detect the object.

A light from a light source is output uniformly in the circumferential direction even if a shift or inclination occurs in a constituent member of a sound signal transmitter. A sound signal transmitter of a microphone includes a light source that outputs a light corresponding to a sound signal from a sound source, a division part that divides the light from the light source into a plurality of divided lights, and a reflector that reflects the divided lights from the division part.

A packaged integrated white light source configured for illumination and communication or sensing comprises one or more laser diode devices. An output facet configured on the laser diode device outputs a laser beam of first electromagnetic radiation with a first peak wavelength. The first wavelength from the laser diode provides at least a first carrier channel for a data or sensing signal.

An energy-harvesting system capable of wireless communication is disclosed which includes a solar cell adapted to generate charge from incident light on the solar cell; an energy-harvesting circuit coupled to the solar cell, the energy-harvesting circuit adapted to convey charge from the solar cell to an energy reservoir; a data communication circuit adapted to encode data to be communicated by the solar cell by adjusting the voltage across the solar cell into at least two states including 1) an open circuit (OC) state, where the current through the solar cell is substantially zero, and 2) a maximum power point (MPP) state, where power (VI) drawn from the solar cell is maximum, wherein the solar cell in response to the changes in its voltage and the incident light emits luminescent radiation with an intensity corresponding to the at least two states, thereby forming a wireless transmitter.

A communication terminal based on free space optical communication, a communication device, and a communication system are provided. The communication system includes a communication terminal, communication devices, and a master control device. The first communication device includes a light emitting unit configured to transmit an optical signal and a second switching control unit configured to establish a connection with the communication terminal that has received the optical signal. The communication terminal includes a light receiving unit configured to receive the optical signal transmitted by the first communication device and a first switching control unit configured to set the first communication device as a switching destination according to the optical signal. The master control device includes a third switching control unit configured to receive a switch request containing identification information of the communication terminal and transmit a connection instruction to the first switching control unit according to the switching request.

A directional free-space optical communication system includes a source device including a laser diode and an endpoint device including a photodiode. The endpoint device and the source device also include an adjustable optics subsystem that increases both angular and positional offset tolerance between the source device and the endpoint device.

A system (100) for providing a user device (102) access to a resource or data is disclosed. The system (100) comprises: the user device (102) comprising: a light detector (104) configured to detect light (130) emitted by a light source (122), which light (130) comprises an embedded code comprising a light source identifier of the light source (122), a communication unit (108) configured to communicate with a network device (112), a processor (106) configured to retrieve the light source identifier from the light (130), and to communicate the light source identifier to the network device (112). The system (100) further comprises the network device (112), comprising: a receiver (114) configured to receive the light source identifier from the user device (102), and a controller (116) configured to identify the light source (122) based on the light source identifier, to encrypt an access key or data with a public key corresponding lo a private key. and to control the light source (122) such that the light (130) comprises an updated embedded code comprising the encrypted access key or the encrypted data. The processor (106) of the user device (102) is further configured to retrieve the encrypted access key or the encrypted data from the updated embedded code comprised in the light (130), and to decrypt the encrypted access key or the encrypted data with the private key, and access the resource with the decrypted access key or retrieve the decrypted data.

The invention relates to a bidirectional wireless communication device which is based on the use of light, including emitting modules, each emitting amplitude- and/or phase-modulated light; and a receiving module made up of: a photodetector illuminated by said modulated light and generating a modulated electrical signal in response to said modulated light; and a processing module for processing the signal generated by said photodetector. The receiving module includes an electronic means positioned between the photodetector and the signal-processing module and capable of matching the impedance of the photodetector to maximise the signal-to-noise ratio of the electrical signal by minimising distortions of said electronic signal associated with incorrect impedance matching at the output of the photodetector, while maximising the level of the modulated electrical signal and the throughput of transmitted data.

A method by a coordination node is disclosed for controlling communications between visible Light Communication, VLC, Access Points, AP, and User Equipments, UEs. The method includes identifying occurrence of an event relating to operation of a first VLC AP. The method further includes determining that a second VLC AP and a third VLC AP each have communication coverage areas that are at least partially within a communication coverage area of the first VLC AP, responsive to identification of occurrence of the event. The method then controls the second and the third VLC APs responsive to the determination to avoid their interfering with communications between the first VLC AP and any UEs within common communication coverage areas of the second or the third VLC APs. Related coordination nodes are disclosed.

A traffic control system consisting of sets of traffic lights each capable of energizing a red, yellow or green traffic light in accordance with the commands issued by an electric traffic controller. The traffic controller being operatively coupled to at least one infrared transmitter configured to send out coded infrared signals which are coordinated to match the traffic mode of the associated traffic lights. The infrared signals being beamed by the infrared transmitter to the vehicular traffic in front of the corresponding traffic light. One or more of these vehicles having an infrared receiver coupled to an LED display, the LED display capable of displaying a red, yellow or green light. The infrared receiver configured to decode the coded binary signals sent by the infrared transmitter and capable to activate a LED light in the display that will match the color of the traffic light that is energized at any given time.