Abstract: An apparatus may provide a control signal based on an axial position of a controller displaceable along an axis. The apparatus may include a component for displacement with said controller along said axis, a radiation source and detector arrangement configured to direct radiation towards a target region and generate a detector signal dependent upon radiation reflected from within that target region, and a computer processor configured to process said detector signal to determine a measure of distance or change of distance to a reflecting surface region within said target region, and to use said measure to provide said control signal. The component may define a reflecting surface that passes through said target region such that a reflecting surface region is present within said target region with a distance that varies with the axial position of the component along said axis.

Abstract: An electro-acoustic transducer includes a membrane, a substrate, and at least one optical device. The at least one optical device is coupled to the substrate for sensing an excursion or velocity of the membrane. The at least one optical device is disposed on an opposite side of the substrate to the membrane.

Abstract: An optical device includes a display and an optical sensor. The display includes display circuitry. The optical sensor is arranged behind the display. The optical sensor includes an emitter for emitting light through the display and a receiver for receiving light reflected back through the display. An absorption of the display is wavelength dependent and the absorption of the display is 50% at a first wavelength. The emitter is configured to emit light at a second wavelength greater than the first wavelength.

Abstract: An electro-acoustic transducer includes a membrane and at least one laser. The at least one laser is configured to emit radiation toward the membrane such that radiation emitted by the at least one laser is reflected from the membrane back toward the at least one laser to produce a self-mixing interference effect corresponding to an excursion or velocity of the membrane.

Abstract: A self-mixing interferometry sensor module, comprising a light emitter (LE), a detector unit (DU) and an optical element (OE), wherein the light emitter (LE) is operable to emit coherent electromagnetic radiation towards an external object (ET) to be placed outside the sensor module and undergo self-mixing interference, SMI, caused by reflections of the emitted electromagnetic radiation from the external object back inside the sensor module. The detector unit (DU) is operable to generate output signals indicative of an optical power output of the light emitter (LE) due to the SMI. The optical element (OE) is aligned with respect to the light emitter (LE) such that a first fraction of electromagnetic radiation is directed towards the external target (ET) or the light emitter (LE) and a second fraction of electromagnetic radiation is directed towards the detector unit (DU). An optical power ratio determined by the first and second fractions meets a pre-determined value.

Abstract: A self-mixing interferometry sensor module, comprising a light emitter (LE), a detector unit (DU) and an optical element (OE), wherein the light emitter (LE) is operable to emit coherent electromagnetic radiation towards an external object (ET) to be placed outside the sensor module and undergo self-mixing interference, SMI, caused by reflections of the emitted electromagnetic radiation from the external object back inside the sensor module. The detector unit (DU) is operable to generate output signals indicative of an optical power output of the light emitter (LE) due to the SMI. The optical element (OE) is aligned with respect to the light emitter (LE) such that a first fraction of electromagnetic radiation is directed towards the external target (ET) or the light emitter (LE) and a second fraction of electromagnetic radiation is directed towards the detector unit (DU). An optical power ratio determined by the first and second fractions meets a pre-determined value.

Abstract: A rotary encoder for providing a control signal in dependence upon an angular position of a controller rotatable about an axis of rotation. The rotary encoder includes a component for rotation with said controller about said axis of rotation. The rotary encoder also includes a radiation source and detector arrangement configured to direct radiation towards a target region and generate a detector signal dependent upon radiation reflected from within that target region. The rotary encoder further includes a computer processor configured to process said detector signal to determine a measure of distance or change of distance to a reflecting surface region within said target region, and to use said measure to provide said control signal. The component defines a reflecting surface that passes through said target region such that a reflecting surface region is present within said target region with a distance that varies with the angular position.

Abstract: Resonant cavity power converters for converting radiation in the wavelength range from 1 micron to 1.55 micron are disclosed. The resonant cavity power converters can be formed from one or more lattice matched GaInNAsSb junctions and can include distributed Bragg reflectors and/or mirrored surfaces for increasing the power conversion efficiency.

Abstract: Semiconductor optoelectronic devices having a dilute nitride active layer are disclosed. In particular, the semiconductor devices have a dilute nitride active layer with a bandgap within a range from 0.7 eV and 1 eV. Photodetectors comprising a dilute nitride active layer have a responsivity of greater than 0.6 A/W at a wavelength of 1.3 ?m.

Abstract: Semiconductor optoelectronic devices having a dilute nitride active region are disclosed. In particular, the semiconductor devices have a dilute nitride active region with at least two bandgaps within a range from 0.7 eV and 1.4 eV. Photodetectors comprising a dilute nitride active region with at least two bandgaps have a reduced dark current when compared to photodetectors comprising a dilute nitride active region with a single bandgap equivalent to the smallest bandgap of the at least two bandgaps.

Abstract: Resonant cavity power converters for converting radiation in the wavelength range from 1 micron to 1.55 micron are disclosed. The resonant cavity power converters can be formed from one or more lattice matched GaInNAsSb junctions and can include distributed Bragg reflectors and/or mirrored surfaces for increasing the power conversion efficiency.

Abstract: Semiconductor optoelectronic devices having a dilute nitride active region are disclosed. In particular, the semiconductor devices have a dilute nitride active region with at least two bandgaps within a range from 0.7 eV and 1.4 eV. Photodetectors comprising a dilute nitride active region with at least two bandgaps have a reduced dark current when compared to photodetectors comprising a dilute nitride active region with a single bandgap equivalent to the smallest bandgap of the at least two bandgaps.

Abstract: Semiconductor structures including optically-transparent metamorphic buffer regions, devices employing such structures, and methods of fabrication. The optically-transparent metamorphic buffer is grown to provide a lattice constant transition between a smaller lattice constant and a larger lattice constant (or vice-versa), allowing materials with two different lattice constants to be monolithically integrated. Such buffer layer may include at least two elements from group V of the periodic table. The optically-transparent metamorphic buffer region may include digital-alloy superlattice structure (s) to confine material defects to the metamorphic buffer layer, and improve electrical properties of the metamorphic buffer layer, thereby improving the electronic properties of electronic devices such as optoelectronic devices and photovoltaic cells. Photonic devices such as solar cells and optical detectors containing such semiconductor structures.

Abstract: Semiconductor optoelectronic devices having a dilute nitride active region and at least one graded or stepped interface layer between the dilute nitride active region and an adjacent higher bandgap semiconductor layer, such as a cladding layer are disclosed. In particular, the semiconductor devices have a dilute nitride active region with at least one bandgap within a range from 0.7 eV and 1.4 eV. Photodetectors comprising a dilute nitride active region with at least one graded or stepped interface layer have a higher carrier collection efficiency and a reduced dark current when compared to photodetectors comprising a dilute nitride active region without a graded or stepped interface layer.

Abstract: Broadband photodetectors, detector arrays, sensors and systems, capable of detection and sensing ultraviolet (UV), visible (VIS) and shortwave infrared (SWIR) wavelengths of light, are disclosed. The devices may operate over a wavelength range between about 0.2 ?m and 1.8 ?m. In particular, the devices include a dilute nitride active layer with a bandgap within a range from 0.7 eV and 1 eV and a luminescent layer.

Abstract: Semiconductor devices and methods of fabricating semiconductor devices having a dilute nitride active layer and at least one semiconductor material overlying the dilute nitride active layer are disclosed. Hybrid epitaxial growth and the use of hydrogen diffusion barrier layers to minimize hydrogen diffusion into the dilute nitride active layer are used to fabricate high-efficiency multijunction solar cells and photonic devices. Hydrogen diffusion barriers can be formed through the use of layer thickness, composition, doping and/or strain.

Abstract: Semiconductor devices and methods of fabricating semiconductor devices having a dilute nitride layer and at least one semiconductor material overlying the dilute nitride layer are disclosed. Hybrid epitaxial growth and the use of aluminum barrier layers to minimize hydrogen diffusion into the dilute nitride layer are used to fabricate high-efficiency multijunction solar cells.

Abstract: Multijunction photovoltaic cells having at least three subcells are disclosed, in which at least one of the subcells comprises a base layer formed of GaInNAsSb. The GaInNAsSb subcells exhibit high internal quantum efficiencies over a broad range of irradiance energies.

Abstract: Semiconductor devices and methods of fabricating semiconductor devices having a dilute nitride active layer and at least one semiconductor material overlying the dilute nitride active layer are disclosed. Hybrid epitaxial growth and the use of hydrogen diffusion barrier layers to minimize hydrogen diffusion into the dilute nitride active layer are used to fabricate high-efficiency multijunction solar cells and photonic devices. Hydrogen diffusion barriers can be formed through the use of layer thickness, composition, doping and/or strain.

Abstract: Semiconductor devices and methods of fabricating semiconductor devices having a dilute nitride layer and at least one semiconductor material overlying the dilute nitride layer are disclosed. Hybrid epitaxial growth and the use of aluminum barrier layers to minimize hydrogen diffusion into the dilute nitride layer are used to fabricate high-efficiency multijunction solar cells.