Abstract: Method and apparatus for detecting, by absorption spectroscopy, an isotopic ratio of a sample, by passing first and second laser beams of different frequencies through the sample. Two IR absorption cells are used, a first containing a reference gas of known isotopic ratio and the second containing a sample of unknown isotopic ratio. An interlacer or reflective chopper may be used so that as the laser frequencies are scanned the absorption of the sample cell and the reference cell are detected alternately. This ensures that the apparatus is continuously calibrated and rejects the baseline noise when phase sensitive detection is used.

Abstract: An accelerated electron detector comprises an array of monolithic sensors in a CMOS structure, each sensor comprising a substrate (10), an epi layer (11), a p+ well (12) and n+ wells (13) which are separated from the p+ well (12) by the epi layer (11). Integrated in the p+ well are a plurality of NMOS transistors. The sensor also includes a deep n region (15) beneath the p+ well (12) which establishes within the epi layer a depletion layer so that on application of a biasing voltage charge carriers generated in the epi layer are caused to drift to the n+ well (13). The detector has improved radiation hardness and it therefore suitable for the detection and imaging of accelerated electrons such as in electron microscopes.

Abstract: Method and apparatus for screening objects using Raman scattering methods to detect the presence of predefined substances or classes of substances. The predefined substances may be hazardous, toxic, or explosive. Radiation is supplied to an incident region of an object. Scattered light is collected from a collection region on the surface of the object spaced from the incident region. The characteristics of the scattered light include Raman features related to the predefined substances. The Raman features allow the presence, or not, of the predefined substances to be determined.

Abstract: A spacecraft is described which uses a magnetic field source to generate a shield magnetic field to protect the spacecraft from energetic charged particles. The field may be perturbed to increase the effectiveness of the protection. Injection of material into the shield cavity to enhance the local plasma density may also be used.

Abstract: An optical sensor (10) comprises an optical cavity defined by a dielectric body and responsive to one or more physical environmental conditions, and a waveguide (70) having a terminal end spaced apart from the optical cavity such that light is optically coupled from the terminal end of the waveguide (70) to the optical cavity. The waveguide (70) is arranged such that, in use, it is maintained at a first temperature that would not damage the optical coupling to the optical cavity when the dielectric body is maintained at a second temperature sufficient to damage the optical coupling to the optical cavity.

Abstract: A Terahertz scanning imaging device for imaging objects where the object is larger than the object to imager distance. The imager comprises scanning elements, sensors, and an image processor. The scanning elements are used to direct radiation to the sensors. Multiple scanning elements and sensors may be used, each scanning a portion of the field of view. The image processor, in communication with the sensors, generates a consolidated 2-dimensional image of a field of view.

Abstract: An optical apparatus comprising a first mirror (12), a second mirror (14), and at least one support (30) for holding the second mirror in substantially a predetermined position relative to said first mirror (12), wherein said at least one support (30) comprises at least one actuator (32) arranged to adjust the position of the second mirror (14), and said optical apparatus further comprises at least one light source (40a-40-c) rigidly fixed to the first mirror (12) in a predetermined orientation for providing a beam of light (42a-42c) directed at said second mirror (14), at least one corresponding alignment sensor (46a-46c) for detecting the beam of light (44a-44c) reflected from said second mirror (14), and arranged to provide an output signal indicative of the position of the incident reflected beam, and a controller (50) arranged to receive said output signal, and to thereby control said actuator (32) to adjust the position of the second mirror (14).

Abstract: An imaging device using an array of active pixels, with a readout control for outputting from selected regions of interest is disclosed. When used to detect the positions of optically trapped objects, the fast readout rate enables fine control of the optical traps to stabilize the objects. Multiple objects can be controlled while being moved relative to each other.

Abstract: An imaging device comprising an array of pixels fabricated using a microelectronic technology such as CMOS is disclosed. The imaging device provides information regarding rapid increases in incident radiation. The sensor is sensitive to a variable quantity to be imaged, such as visible or non-visible radiation, and a signal representative of the quantity is output. The quantity is measured over a monitoring period, and the timing of the incidence may also be output.

Abstract: Methods and apparatus for screening the unknown contents of containers using Raman spectroscopy are disclosed, especially for security screening applications such as in airports. A probe light beam is directed through the wall of a container to a sample region within the container contents. Light scattered out of the beam within the sample region is collected along a path which passes through a separate part of the container wall, for Raman spectral analysis.

Abstract: A dough moulding composition for use in the manufacture of ballistic armour comprising a boron carbide particulate and a polymeric binder, wherein the boron carbide particulate exhibits a particle size distribution in which some of the particles have a particle size of 100 ?m or more and some of the particles have a particle size of 50 ?m or less.

Abstract: Apparatus and methods for detecting Raman spectral features non destructively from sub-surface regions of a diffusely scattering sample are disclosed. Incident radiation is supplied at one or more sample surface entry regions, and light is collected from one or more collection regions spaced from the entry regions. Raman features are detected in the collected light, and depth information is derived according to the entry-collection spacings.

Abstract: The present invention relates to a method of generating a lipid profile for a sample solution. The method comprising: a first step of determining the concentration of total lipoprotein in a first aliquot of the sample using fluorescence analysis; a second step of determining the concentration of total cholesterol in a second aliquot of the sample using fluorescence analysis; and optionally a third step of determining the concentration of HDL in a third aliquot of the sample using fluorescence analysis. The concentrations of the total lipoprotein, and of total cholesterol may be used to calculate other lipid components and thereby generate a lipid profile. The invention also concerns apparatus that may be used to perform the method of the invention.

Abstract: Non invasive in-vivo measurement of composition of a tissue within a part of a human or animal subject is carried out by detecting a Raman spectral characteristic in light scattered through the part using a transmission, rather than a backscattering geometry. The technique is applied to the detection of calcifications in human breast tissues.

Abstract: The terahertz camera has a fixed objective lens (2) and a plurality of detectors (3) positioned at the focal plane of the objective lens (2). Each of the detectors (3) is mounted on a movable support (10) so that the antenna is capable of movement across the focal plane of the objective lens (2) and is provided with a flexible waveguide (4) for connecting the output of the detector (3) with signal processing means. Each detector (3) is also provided with a retroreflector (6) which is reflective at frequencies other than terahertz frequencies. During use of the camera, the retroreflector (6) of each detector (3) is illuminated at non-terahertz frequencies so that the spatial position of each detector (3) and hence the spatial source of signals generated by the detector can be accurately identified. The terahertz camera is particularly suited for use in security installations and in chemical and food processing industries.

Abstract: A method of producing NH2 (R2), the method comprising reacting a metal hydride with a compound having the general formula: M1x (BH4)y (NH2 (R2))n wherein M1 comprises one or more of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, La, Al, Ga and Sc; 0<n?4; R2 comprises —H, alkyl and an aromatic substituent; and x and y are selected so as to maintain electroneutrality.

Abstract: A device for manipulation by a plurality of optical traps is disclosed. Connected trapping elements such as transparent beads are also connected to a tip, which is spaced from the trapping elements by a distance greater than the effective range of the optical trapping fields.

Abstract: A detection system includes a modulator to apply a circular polarization modulation to an incident beam of radiation, a sample holder through which the modulated beam is pass, a grating to diffract the beam of radiation, an array of solid state detectors arranged to receive different wavelengths of the beam, and a process arranged to synchronise detected signals with the modulation applied by the modulator, in order to measure the spectral circular dichroism of the sample.

Abstract: Method and apparatus for detecting, by absorption spectroscopy, an isotopic ratio of a sample, by passing first and second laser beams of different frequencies through the sample. Two IR absorption cells are used, a first containing a reference gas of known isotopic ratio and the second containing a sample of unknown isotopic ratio. An interlacer or reflective chopper may be used so that as the laser frequencies are scanned the absorption of the sample cell and the reference cell are detected alternately. This ensures that the apparatus is continuously calibrated and rejects the baseline noise when phase sensitive detection is used.

Abstract: Apparatus and methods for detecting Raman spectral features non destructively from sub-surface regions of a diffusely scattering sample are disclosed. Incident radiation is supplied at one or more sample surface entry regions, and light is collected from one or more collection regions spaced from the entry regions. Raman features are detected in the collected light, and depth information is derived according to the entry-collection spacings.