Abstract: A position detection system is able to detect the three dimensional position of at least one target (10). Each target (10) is configured to act as a retro-reflector for light incident from any direction. At least one light emitter illuminates the at least one target (10) and at least one detector (24) is provided for detecting and taking measurements of light retro-reflected from a target (10). There is also provided a processor for processing measurements taken by each detector (24) to determine the three dimensional position of the at least one target (10).

Abstract: A measurement device (120) includes a light director and a spatial light modulator (130). The light director is disposed to direct light to the spatial light modulator (130) and the spatial light modulator (130) is disposed to receive light from the light director and to modulate it to form an intensity pattern. An optical element is disposed to receive light which formed the intensity pattern and is arranged to magnify the intensity pattern into a measurement space. A detector (142) is disposed to detect light reflected from the measurement space.

Abstract: A measurement device comprises a high permittivity dielectric resonator (10) with a low microwave loss tangent and having at least a first symmetry axis (z-i); an electrically conductive resonance chamber (100) containing and geometrically similar to the resonator (10) and having a second symmetry axis (z2) coincident with the first symmetry axis (z-i); the resonance chamber (100) having a plurality of similar ports (104) orthogonal to the first symmetry axis (z-i), each such port (104) having a microwave antenna (114), either to inject microwaves into the resonance chamber, thereby to excite an electric field in the resonator, or to receive microwaves from the resonance chamber; and a comparator circuit (200, 300, 400, 500, 600, 700, 800) connected to a first one (P1) of the plurality of ports (104) to inject microwaves into the resonance chamber and to another (P2, P3) of the plurality of ports (104) to receive microwaves from the resonance chamber; wherein the measurement device further comprises an electr

Abstract: A maser assembly includes a pump light source; a maser material including molecules that are excited through the absorption of light (1) from the pump light source, and which subsequently transfer via intersystem crossing (9) into the sublevels of their triplet ground states, so causing a population inversion between two sublevels (16,18); an electromagnetic structure in which the masing material is disposed, and which supports a microwave mode that is both resonant in frequency with and magnetically coupled to the transition between these two sublevels; and where energy is supplied to the microwave mode through stimulated emission (25) across the transition at such a rate as to exceed the mode's electromagnetic losses, the microwave mode being a maser mode. The assembly includes provisions for effecting substantially continuous maser activity during operation of the assembly.

Abstract: A Fabry-Perot etalon is provided with first and second partially reflecting mirrors (12, 14) attached to a cuboidal spacer (16). The spacer (16) has a cylindrical bore (18) through its center and the mirrors (12, 14) are bonded, on axis, to opposite ends of this bore (18). Four support elements (22-28) are arranged symmetrically with respect to the axis in a tetrahedral configuration and constrain the cuboidal spacer (16) in all degrees of freedom. The cuboidal spacer (16) is flattened at its vertices, which results in modified distortion of the spacer (16) under the action of a compressive force acting through the supports. This structure of etalon provides insensitivity to inertial forces due to acceleration in all six degrees of freedom (three linear and three rotational) simultaneously with insensitivity to differential forces.

Abstract: A cyclic peptide (10) includes two domains (D1,D2), each including three charged sub-domains (14, 16). The first domain (D1) includes two anionic sub-domains (14) followed by a cationic sub-domain (16). The second domain (D2) includes two cationic sub-domains (16) followed by an anionic sub-domain (14). The two domains are connected to one another and separated by a tri-glycyl linker (12). The cyclic peptide (10) is able to self-assemble into a network able to mimic an extracelluar matrix, and which promotes cell growth whilst resisting biofilm formation.

Abstract: A maser assembly includes a pump light source; a maser material including molecules that are excited through the absorption of light (1) from the pump light source, and which subsequently transfer via intersystem crossing (9) into the sublevels of their triplet ground states, so causing a population inversion between two sublevels (16,18); an electromagnetic structure in which the masing material is disposed, and which supports a microwave mode that is both resonant in frequency with and magnetically coupled to the transition between these two sublevels; and where energy is supplied to the microwave mode through stimulated emission (25) across the transition at such a rate as to exceed the mode's electromagnetic losses, the microwave mode being a maser mode. The assembly includes provisions for effecting substantially continuous maser activity during operation of the assembly.

Abstract: Aerosol detection apparatus comprises an aircraft having a dielectric member, such as a window (10), comprised in the body (12) thereof such that a surface of the dielectric member forms part of the exterior surface of the aircraft. Detection means (16), such as a static monitor is located on the inside of the aircraft and arranged to detect an electric field resulting from polarization of the dielectric member. The output of the static monitor, or the rate of change thereof, correlates closely to particle density as the aircraft is flown though an aerosol, such as a volcanic ash cloud. The apparatus is simple and relatively inexpensive, and may comprise any general purpose aircraft. Aerosol particles may be detected and mapped using apparatus of the invention more easily and quickly than by use of devices such as optical spectrometers mounted on dedicated research aircraft, or static monitors mounted on the exterior of an aircraft.

Abstract: A smart antenna assembly includes a driving monopole element and an array of parasitic monopole elements arranged in an annular array around the driving monopole element, wherein the parasitic monopole elements are of bent or curved configuration, bending or curving towards the driving monopole element. Preferably, each parasitic monopole element has a portion thereof which is parallel or substantially parallel to the driving monopole element. The assembly provides a compact steerable antenna assembly.

Abstract: A substrate includes a diffracting structure providing a hologram (20, 6). The diffracting structure encodes a holographic image so that thatholographic image is produced in response to reference light being incident on a major surface of the substrate at an angle of incidence with respect to the said major surface of the substrate, wherein the angle of incidence is no more than 20°.

Abstract: A system for obtaining a propagation factor for determining the performance of a light beam (32) includes a light sensor (10), a lens element (30) operable to focus a beam from a light source to be tested towards the sensor element (10); wherein the lens element is a variable focus lens (30).

Abstract: A sensor system includes a sensor and processing means adapted to process the signals from the sensor, and to provide a distance measurement or estimate from the sensor to a metallic object of interest, such as a turbine blade. The sensor, typically an eddy current sensor, provides a signal to which the processing means fits a curve, and parameters including pulse width and height are taken from the fitted curve and used in calculating the distance measurement or estimate. Look-up tables may be used to produce the measurement or estimate. Average values of the parameters may calculated to reduce random noise effects and may be subsequently used to produce correction factors to correct instantaneous measurements.

Abstract: A semiconductor device comprising a plurality of regions of semiconductor material forming a junction at an interface there-between, the junction including a depletion region having a width which varies spatially in at least one direction along the depletion region. Without limitation, the spatial variation in depletion region width is provided by ionised dopants having a concentration which varies spatially along said at least one direction. Alternatively, or in addition, the spatial variation in depletion region width is achieved by varying the thickness of the region(s) of semiconductor spatially along said at least one direction, for example by creating a plurality of cells within said region(s) devoid of said semiconductor material. A method of fabricating a semiconductor device comprising the step of varying the width of the depletion region spatially there-within in at least one direction along the depletion region.