Abstract: An interface or communications system for a neural probe, the interface or communications system comprising at least one probe interface, an optical communications interface and a processing system. The at least one probe interface is configured to interface with at least one neural probe so as to receive data collected by the probe. The processing system is configured to process the data from the at least one probe interface and provide the processed data to the optical communications interface. The optical communications interface is configured to communicate the processed data to a remote device, e.g. using optical wireless communications. The optical communications interface has the large bandwidth available that will allow the scaling up of recording sites from the neural probe without resulting in undue size, weight and/or power consumption.

Abstract: An interface or communications system for a neural probe, the interface or communications system comprising at least one probe interface, an optical communications interface and a processing system. The at least one probe interface is configured to interface with at least one neural probe so as to receive data collected by the probe. The processing system is configured to process the data from the at least one probe interface and provide the processed data to the optical communications interface. The optical communications interface is configured to communicate the processed data to a remote device, e.g. using optical wireless communications. The optical communications interface has the large bandwidth available that will allow the scaling up of recording sites from the neural probe without resulting in undue size, weight and/or power consumption.

Abstract: There is herein described light emitting medical devices and a method of manufacturing said medical devices. More particularly, there is described integrated light emitting medical devices (e.g. neural devices) capable of being used in optogenetics and a method of manufacturing said medical devices.

Abstract: A polycrystalline CVD diamond material comprising a surface having a surface roughness Rq of less than 5 nm, wherein said surface is damage free to the extent that if an anisotropic thermal revealing etch is applied thereto, a number density of defects revealed by the anisotropic thermal revealing etch is less than 100 per mm2.

Abstract: A polycrystalline CVD diamond material comprising a surface having a surface roughness Rq of less than 5 nm, wherein said surface is damage free to the extent that if an anisotropic thermal revealing etch is applied thereto, a number density of defects revealed by the anisotropic thermal revealing etch is less than 100 per mm2.

Abstract: There is herein described light emitting medical devices and a method of manufacturing said medical devices. More particularly, there is described integrated light emitting medical devices (e.g. neural devices) capable of being used in optogenetics and a method of manufacturing said medical devices.

Abstract: The present invention relates to a method of producing a diamond surface including the steps of providing an original diamond surface, subjecting the original diamond surface to plasma etching to remove at least 2 nm of material from the original surface and produce a plasma etched surface, the roughness Rq of the plasma etched surface at the location of the etched surface where the greatest depth of material has been removed satisfying at least one of the following conditions: Rq of the plasma etched surface is less than 1.5 times the roughness of Rq of the original surface, or Rq of the plasma etched surface is less than 1 nm.

Abstract: An ultra violet light transmitting polymer is obtainable by the polymerisation of at least one compound having a substantially non UV absorbing core group comprising; linear or branched aliphatic hydrocarbons which may contain an aliphatic ring; or polydialkylsiloxanes. The compounds have at least one functional group comprising formula (A), (B) or (C):and each of the groups —R3— are, independently, linking groups which may be present or absent and, where present, may be a C1 to C10 hydrocarbon chain, which may contain an ether linkage. Methods for producing the polymers and uses for the polymers are also described.

Abstract: The present invention relates to a method of producing a diamond surface including the steps of providing an original diamond surface, subjecting the original diamond surface to plasma etching to remove at least 2 nm of material from the original surface and produce a plasma etched surface, the roughness Rq of the plasma etched surface at the location of the etched surface where the greatest depth of material has been removed satisfying at least one of the following conditions: Rq of the plasma etched surface is less than 1.5 times the roughness of Rq of the original surface, or Rq of the plasma etched surface is less than 1 nm.

Abstract: An array of light emitting devices, each device comprising a sloped wall mesa (24) of luminescent semiconductor material. Extending over the sloped wall mesas (24) is a metal contact (30). The array can be arranged as a parallel addressable system so that all devices (24) can be stimulated to emit light simultaneously. Alternatively, the array can be arranged as a matrix addressable array, in which case individual devices can be selectively stimulated.

Abstract: A vertical-cavity device comprises: (a) a chip comprising an active semiconductor layer for providing optical gain; (b) a first mirror arranged on a first side of the active layer; (c) a second mirror arranged on a second side of the active layer, opposite to the first mirror, and forming with at least the first mirror an optically resonant cavity that passes through the active layer in a direction out of the plane of the active layer; (d) a heatspreader for removing heat from the active layer, the heatspreader being arranged inside the cavity and having a first surface adjacent to the chip and a second surface opposite to the first surface, the heatspreader being transparent to light of wavelengths in an operating bandwidth of the device. In addition to removing heat from the active layer, the heatspreader also has one or more further selected property that has a further selected effect on light output from the device.

Abstract: A solid-state, surface-emitting, optical device such as a light emitting diode (LED) or vertical cavity surface emitting laser (VCSEL) has a body of optical gain medium overlying a high reflectivity distributed BRAGG reflector (DBR) mirror which is carried on part of an underlayer. The gain layer is part of an epitaxial layered structure extending from the underlayer and over the mirror.

Abstract: A solid-state, surface-emitting, optical device such as a light emitting diode (LED) or vertical cavity surface emitting laser (VCSEL) has a body of optical gain medium overlying a high reflectivity distributed BRAGG reflector (DBR) mirror which is carried on part of an underlayer. The gain layer is part of an epitaxial layered structure extending from the underlayer over the mirror.

Abstract: A semiconductor optical amplifier comprising an active gain region of the (In, Ga)(As, N) system is proposed, together with the use of (Ga, In)(As, N) as the base material for the fabrication of an SOA, and a semiconductor optical amplifier comprising (Ga, In)(As, N) as the base material. The N content of the (In, Ga)(As, N) can be varied along a dimension of the active region in the direction of propagation of light signals therein, to create a varying bandgap such as for mode expanders. The active region can be supplied by a source of electrical bias which is applied in segments along the dimension of the active region, the segments being capable of independent variation. This should allow channel equalisation of WDM signals to be performed dynamically. This scheme could also be used to equalise device parameters such as differential gain, saturation output power and linewidth enhancement factor across the amplification bandwidth.

Abstract: A semiconductor optical amplifier comprising an active gain region of the (In, Ga)(As, N) system is proposed, together with the use of (Ga,In)(As,N) as the base material for the fabrication of an SOA, and a semiconductor optical amplifier comprising (Ga,In)(As,N) as the base material. The N content of the (In,Ga)(As,N) can be varied along a dimension of the active region in the direction of propagation of light signals therein, to create a varying bandgap such as for mode expanders. The active region can be supplied by a source of electrical bias which is applied in segments along the dimension of the active region, the segments being capable of independent variation. This should allow channel equalisation of WDM signals to be performed dynamically. This scheme could also be used to equalise device parameters such as differential gain, saturation output power and linewidth enhancement factor across the amplification bandwidth.

Abstract: A lasing structure comprises a distributed feedback grating associated with the active region, the grating defined by a periodic structure of quantum well intermixing. This quantum well intermixing (QWI) can be caused by focussed ion beam (FIB) implantation to the quantum well (QW) or multi-quantum well (MQW) active area. Subsequent annealing of the FIB damage will leave local periodic adjustments to the energy levels in the active region, providing the necessary DFB/DBR grating. Alternatively, or in addition, this periodic QWI structure or another periodic variation can be separated from the active region but associated therewith. For example, a QW or MQW structure which overlies the active region will carry the evanescent part of the waveform that is propagating in the active region. A periodic QWI structure in this region will thus affect the waveform.

Abstract: The light emitted by diodes of the Gallium Nitride type which comprises two distinguishable emissions is controlled by a single optical element (10) in the form of a lens having a central part and an annular part with different optical powers. The total output light of the diode may be collimated or brought to a common focus. The single optical element is preferably injection moulded and the annular part takes the form of a diffraction lens. The first part (12) is preferably a refractive lens which has a different optical power to the second part (14)which is preferably a diffractive lens. The optical power of the refractive lens (12) (the first optical power) and the optical power of the diffractive lens (14) (the second optical power) are selected to match the light source that the lens (10) is to be used with.

Abstract: A single cavity mode optoelectronic device, such as a VCSEL, an RCLED or a DFB laser diode, comprises an etched-pillar or mesa structure including an optically active region and strain-applying means in the form of a layer of polymer material having a coefficient of thermal expansion which is greater than that of the optically active region. The layer surrounds the optically active region so as to apply a compressive strain to the latter so as to compensate at least partially for temperature-induced changes in the gain spectrum peak of the optically active region caused by ohmic heating of the device.

Abstract: A surface-emitting laser contains an optical cavity including a multiple quantum well (MQW) active region providing a source of optical emission in use. Top and bottom mirrors are disposed respectively above and below the MQW active region. The MQW active region is profiled so that it has a greater number of quantum wells in a central portion thereof than in a peripheral portion thereof. In alternative embodiments, a current-guiding region is profiled so that it has a first current-guiding portion with a relatively smaller aperture therethrough extending over a central portion of the MQW active region, and a second current-guiding portion with a relatively larger aperture therethrough; and one of the mirrors has a layer structure which, in a central portion of the cross-sectional area of such mirror, is different to that in a peripheral portion of said cross-sectional area.