Abstract: An acousto-optic transducer comprises a graphene resonator, a substrate, an entry window and an exit window. The graphene resonator bears at least one donor molecule. The substrate bears at least one acceptor molecule. The graphene resonator is responsive to sound to bring the at least one donor molecule within range of the at least one acceptor molecule for Förster resonance energy transfer from the at least one donor molecule to the at least one acceptor molecule to take place. The entry window is arranged to permit incoming light to fall on the at least one donor molecule. The exit window is arranged to allow light emitted by the at least one acceptor molecule to leave the acousto-optic transducer. Thus, the acousto-optic transducer can function as a passive device using only energy derived from ambient light to convert sound into light.

Abstract: An identification tag has at least one molecule of a first type and at least one molecule of a second type. The molecules are capable of energy transfer according to Förster Resonance Energy Transfer, with one of the types being donor molecules and the other type being acceptor molecules. The tag has a substrate which has a plurality of locations at which molecules of the second type may be located. The light intensity emitted by the acceptor molecule(s) as the molecule of the first type is moved across the locations varies in dependence on whether a molecule of the second type is or is not located in the locations.

Abstract: The present disclosure provides a visible light communication transmitter, a visible light communication receiver, a visible light communication system, and a method of visible light communication, which are suitable for colour shift keying (CSK), as well as providing a method of CSK. The transmitter comprises at least six graphene-based light emitting devices of different peak transmission wavelengths from each other. The receiver comprises a corresponding number of graphene-based photodetectors of different peak reception wavelengths from each other. A system according to the disclosure comprises such a transmitter and such a receiver, wherein each respective one of the different peak reception wavelengths of the six graphene-based photodetectors corresponds to a respective one of the different peak transmission wavelengths of the graphene-based light emitting devices. Such a system allows a method of visible light communication with a colour constellation of at least six base colours.

Abstract: An identification tag has at least one molecule of a first type and at least one molecule of a second type. The molecules are capable of energy transfer according to Förster Resonance Energy Transfer, with one of the types being donor molecules and the other type being acceptor molecules. The tag has a substrate which has a plurality of locations at which molecules of the second type may be located. The light intensity emitted by the acceptor molecule(s) as the molecule of the first type is moved across the locations varies in dependence on whether a molecule of the second type is or is not located in the locations.

Abstract: An acousto-optic transducer comprises a graphene resonator, a substrate, an entry window and an exit window. The graphene resonator bears at least one donor molecule. The substrate bears at least one acceptor molecule. The graphene resonator is responsive to sound to bring the at least one donor molecule within range of the at least one acceptor molecule for Förster resonance energy transfer from the at least one donor molecule to the at least one acceptor molecule to take place. The entry window is arranged to permit incoming light to fall on the at least one donor molecule. The exit window is arranged to allow light emitted by the at least one acceptor molecule to leave the acousto-optic transducer. Thus, the acousto-optic transducer can function as a passive device using only energy derived from ambient light to convert sound into light.

Abstract: The present disclosure provides a visible light communication transmitter, a visible light communication receiver, a visible light communication system, and a method of visible light communication, which are suitable for colour shift keying (CSK), as well as providing a method of CSK. The transmitter comprises at least six graphene-based light emitting devices of different peak transmission wavelengths from each other. The receiver comprises a corresponding number of graphene-based photodetectors of different peak reception wavelengths from each other. A system according to the disclosure comprises such a transmitter and such a receiver, wherein each respective one of the different peak reception wavelengths of the six graphene-based photodetectors corresponds to a respective one of the different peak transmission wavelengths of the graphene-based light emitting devices. Such a system allows a method of visible light communication with a colour constellation of at least six base colours.