Abstract: An optical wireless communication (OWC) unit for transmitting and/or receiving data installable in a further device comprises at least one transmitter device for transmitting modulated light comprising an OWC signal of said data and/or at least one receiver device for receiving modulated light comprising an OWC signal representative of said data, wherein the at least one receiver device comprises at least one detector. The OWC unit further comprises analogue electronic circuitry for processing electronic signals and at least one power connection and/or at least one data connection for connection to a power source and/or processing resource of the further device. The OWC unit is operable to provide OWC communication under control of said further device and/or so as to transmit data from/provide data to said further device. The OWC unit is for use in an OWC system having an analogue bandwidth greater than or equal to 80 MHz.

Abstract: An optical wireless communication (OWC) device comprises: a receiver comprising: a dual-wavelength filter configured to filter light arriving at the receiver, wherein the dual-wavelength filter is configured to pass light of a first frequency and light of a second, different frequency, and wherein the dual-wavelength filter is configured to substantially block light of a third frequency between the first frequency and second frequency; and a photodetector configured to receive the filtered light and to sense modulated light of the first frequency and/or modulated light of the second frequency to produce at least one receiver signal; demodulation circuitry and a processing resource for performing a demodulation and processing with respect to the at least one receiver signal to obtain data encoded in the modulated light of the first frequency and/or data encoded in the modulated light of the second frequency; a transmitter comprising a light source configured to output modulated light of the third frequency; a

Abstract: A display apparatus comprises an at least partially transparent display, the display configured to generate light to form an image for display to a user positioned in front of the display, and at least one light-transmitting and/or light-receiving device positioned behind the display, wherein the at least one light-transmitting and/or light-receiving device is configured to transmit and/or receive light through at least part of the display, wherein the at least one light-transmitting and/or light-receiving device comprises or forms part of an optical wireless communications (OWC) apparatus configured to transmit and/or receive the light through the at least part of the display.

Abstract: A display apparatus comprises an at least partially transparent display, the display configured to generate light to form an image for display to a user positioned in front of the display, and at least one light-transmitting and/or light-receiving device positioned behind the display, wherein the at least one light-transmitting and/or light-receiving device is configured to transmit and/or receive light through at least part of the display, wherein the at least one light-transmitting and/or light-receiving device comprises or forms part of an optical wireless communications (OWC) apparatus configured to transmit and/or receive the light through the at least part of the display.

Abstract: An optical wireless communication (OWC) device comprises: a receiver comprising: a dual-wavelength filter configured to filter light arriving at the receiver, wherein the dual-wavelength filter is configured to pass light of a first frequency and light of a second, different frequency, and wherein the dual-wavelength filter is configured to substantially block light of a third frequency between the first frequency and second frequency; and a photodetector configured to receive the filtered light and to sense modulated light of the first frequency and/or modulated light of the second frequency to produce at least one receiver signal; demodulation circuitry and a processing resource for performing a demodulation and processing with respect to the at least one receiver signal to obtain data encoded in the modulated light of the first frequency and/or data encoded in the modulated light of the second frequency; a transmitter comprising a light source configured to output modulated light of the third frequency; a

Abstract: A display apparatus comprises an at least partially transparent display, the display configured to generate light to form an image for display to a user positioned in front of the display, and at least one light-transmitting and/or light-receiving device positioned behind the display, wherein the at least one light-transmitting and/or light-receiving device is configured to transmit and/or receive light through at least part of the display, wherein the at least one light-transmitting and/or light-receiving device comprises or forms part of an optical wireless communications (OWC) apparatus configured to transmit and/or receive the light through the at least part of the display.

Abstract: A display apparatus comprises an at least partially transparent display, the display configured to generate light to form an image for display to a user positioned in front of the display, and at least one light-transmitting and/or light-receiving device positioned behind the display, wherein the at least one light-transmitting and/or light-receiving device is configured to transmit and/or receive light through at least part of the display, wherein the at least one light-transmitting and/or light-receiving device comprises or forms part of an optical wireless communications (OWC) apparatus configured to transmit and/or receive the light through the at least part of the display.

Abstract: An optical wireless communication (OWC) receiver apparatus for receiving data streams from at least one transmitter apparatus, each data stream encoded on abeam of light of a respective different wavelength or range of wavelengths propagating through free space between the at least one transmitter apparatus and the receiver apparatus, the apparatus comprising: a wavelength-selective element configured to receive the beams after their propagation through free space and to direct a selected at least one of the beams having a selected wavelength or range of wavelengths to a detector, wherein the detector is configured to receive said selected at least one of the beams and in response to output a detection signal; at least one control element operable to control at least one physical property of the wavelength-selective element thereby to select said at least one of the beams for direction to the detector.

Abstract: An optical wireless communication (OWC) receiver apparatus for receiving data streams from at least one transmitter apparatus, each data stream encoded on abeam of light of a respective different wavelength or range of wavelengths propagating through free space between the at least one transmitter apparatus and the receiver apparatus, the apparatus comprising: a wavelength-selective element configured to receive the beams after their propagation through free space and to direct a selected at least one of the beams having a selected wavelength or range of wavelengths to a detector, wherein the detector is configured to receive said selected at least one of the beams and in response to output a detection signal; at least one control element operable to control at least one physical property of the wavelength-selective element thereby to select said at least one of the beams for direction to the detector.

Abstract: A display apparatus comprises an at least partially transparent display, the display configured to generate light to form an image for display to a user positioned in front of the display, and at least one light-transmitting and/or light-receiving device positioned behind the display, wherein the at least one light-transmitting and/or light-receiving device is configured to transmit and/or receive light through at least part of the display, wherein the at least one light-transmitting and/or light-receiving device comprises or forms part of an optical wireless communications (OWC) apparatus configured to transmit and/or receive the light through the at least part of the display.

Abstract: A Precision Approach Path Indicator (PAPI) unit comprises first and second light sources and a projection lens assembly. Light emitted by the first and second light sources is collected by first and second solid waveguides respectively and is guided by said waveguides to an intermediate plane. The intermediate plane is located in the focal plane of the projection lens assembly.

Abstract: Apparatus for laser processing a material (8) with optical radiation (T), which apparatus comprises a seed laser (1) pumped by a seed pump (2), an amplifier (3) pumped by an amplifier pump (4), a controller (5), and a scanner (6), wherein the controller (5) controls the seed pump (2), the amplifier pump (4) and the scanner (6) in synchronism such that optical pulses (10) emitted by the seed laser (1) are propagated through the amplifier (3) and directed to the material (8) by the scanner (6), the apparatus being characterized in that controller (5) controls the amplifier pump (4) to cause the amplifier (3) to act as an optical attenuator when the optical radiation (7) is in a first power range, and as an optical amplifier when the output power is in a second power range.

Abstract: This invention provides a flat dispersion frequency discriminator (FDFD) capable of having a substantially flat dispersion with either a positive or negative dispersion along the spectrum region of the discriminator. This way, a FDFD may not cause substantial distortion of the intensity patter of its output to minimize the occurrence distortion due to overshooting or undershooting of the intensity pattern depending on the relative spectral alignment of the laser output relative to the filter transmission.

Abstract: This invention provides a flat dispersion frequency discriminator (FDFD) capable of having a substantially flat dispersion with either a positive or negative dispersion along the spectrum region of the discriminator. This way, a FDFD may not cause substantial distortion of the intensity patter of its output to minimize the occurrence distortion due to overshooting or undershooting of the intensity pattern depending on the relative spectral alignment of the laser output relative to the filter transmission.

Abstract: This invention provides a flat dispersion frequency discriminator (FDFD) capable of having a substantially flat dispersion with either a positive or negative dispersion along the spectrum region of the discriminator. This way, a FDFD may not cause substantial distortion of the intensity patter of its output to minimize the occurrence distortion due to overshooting or undershooting of the intensity pattern depending on the relative spectral alignment of the laser output relative to the filter transmission.