Abstract: A transmission line arrangement having a first end and a second end, the transmission line arrangement being configured to transmit a signal between the first end and the second end, the transmission line arrangement comprising a signal conductor extending between the first end and the second end of the transmission line arrangement, a first conducting sheet and a second conducting sheet positioned on two opposing sides of the signal conductor, an insulating material separating the first and second conducting sheets from the signal conductor and a plurality of pieces of conducting material extending between the first and second conducting sheets and arranged at different positions between the first and second ends of the transmission line arrangement, wherein the pieces of conducting material and the conducting sheets are arranged to substantially surround the signal conductor for at least part of its length between the first and second ends of the transmission line arrangement.

Abstract: A test system for testing a device having a plurality of electrical contacts. The test system comprising: a device table operable to hold at least one device under test, a probe comprising at least one probe end for contacting electrical contacts of a device under test, a movement mechanism operable to move one or both of the device table and the probe so as to bring the at least one probe end into contact with at least one electrical contact of a device under test, and a profile determining system configured to determine a profile of the electrical contacts of a device under test.

Abstract: A range of technique for investigating a sample such as obtaining images and/or spectral information are described. The techniques include a method for deriving structural information about a sample as a continuous function of the depth below the surface of the sample, a method for evaluating a part of the structure of a sample located between two interfaces within the sample, and a contrast enhancing method and apparatus which has a quick image acquisition time.

Abstract: A reflectometer for allowing a test of a device, the reflectometer comprising: a source of pulsed radiation; a first photoconductive element configured to output a pulse in response to irradiation from said pulsed source; a second photoconductive element configured to receive a pulse; a transmission line arrangement configured to direct the pulse from the first photoconductive element to the device under test and to direct the pulse reflected from the device under test to the second photoconductive element; and a termination resistance provided for said transmission line configured to match the impedance of the transmission line.

Abstract: Imaging techniques of pharmaceutical preparations such as tablets are disclosed. The techniques combine the measurement of reflected/transmitted terahertz radiation originating from within the tablet and data analysis localized in frequency and time in order to enable a three dimensional image indicating composition to be obtained.

Abstract: A method of performing dissolution analysis on a tablet, the method comprising: irradiating a tablet with radiation having at least one frequency in the range from 40 GHz to 100 THz; detecting radiation which has been transmitted through or reflected by the tablet; determining a parameter from the detected radiation indicative of the density of a coating layer of the tablet; and determining information about the dissolution characteristics of the tablet from said parameter.

Abstract: A probe array (1) for an imaging system for examining an object (19) comprising at least one emitter (7) for emitting radiation, a plurality of detectors (9) for detecting radiation and means for directing radiation emitted by the at least one emitter (7) to the object (19) and for directing radiation reflected from the object (19) to at least two of the plurality of detectors (9) wherein in use the emitted radiation is scanned by means (21) across the object (19).

Abstract: A THz radiation probe (1) for examining an object (8), the probe comprising a first portion configured to be inserted into an opening of said object in a first direction (5), said probe further comprising at least one THz emitter (15), directing means (7) for directing THz radiation emitted from said emitter to said object via an aperture (2) located at said first portion and subsequently from said object to at least one THz detector (17) and, means for scanning said emitted THz radiation across said object in a scan direction, said scan direction having a component in said first direction (5).

Abstract: Method and apparatus for investigating a sample particularly a pharmaceutical tablet. An emitter and/or the sample are initially positioned so that the emitter is at a predetermined distance and normal angle to a first point on a surface of the sample. The emitter then irradiates the sample with radiation having a plurality of frequencies in the range from 25 GHz to 100 THz at a plurality of points on the surface of the sample. Relative motion is possible between the emitter and the sample so that the surface of the sample can be tracked to maintain the predetermined distance and normal angle at each of the plurality of points, and allow radiation transmitted and/or reflected from the sample at the plurality of points to be detected. This has particular application to imaging the structure or composition of a coating on a pharmaceutical tablet.

Abstract: A reflectometer for allowing a test of a device, the reflectometer comprising: a source of pulsed radiation; a first photoconductive element configured to output a pulse in response to irradiation from said pulsed source; a second photoconductive element configured to receive a pulse; a transmission line arrangement configured to direct the pulse from the first photoconductive element to the device under test and to direct the pulse reflected from the device under test to the second photoconductive element; and a termination resistance provided for said transmission line configured to match the impedance of the transmission line.

Abstract: A system for investigating a plurality of samples having varying positions or orientations moving with respect to the system, the system including an emitter of terahertz radiation for irradiating a sample provided in a sample space; a detector of terahertz radiation configured to detect radiation reflected from said sample space; and determining means to determine if radiation reflected from said sample space is from a sample with a predetermined orientation in the sample space.

Abstract: An apparatus for investigating a sample comprising: a source of beam radiation; a detector for detecting a beam of radiation reflected by the sample and an optical subsystem for manipulating the beam between source and detector wherein the optical subsystem comprises a first optical element arranged in use to angularly deflect the source beam within a given solid angle and a second optical element arranged to focus the beam from the first optical element onto a substantially flat image plane and wherein radiation reflected by the sample passes back through the first and second optical elements to the detector.

Abstract: Apparatus for measurement of a sample comprises means for generating electromagnetic radiation comprising a photoconductive device, the generating means is arranged to generate an output signal comprising electromagnetic radiation in dependence upon radiation received by the photoconductive device and to transmit the output signal towards a sample space, the apparatus further comprises a first radiation source and a second radiation source, arranged such that the radiation received by the photoconductive device comprises a mixture of radiation from the first radiation source and radiation from the second radiation source, control means for varying the frequency of the electromagnetic radiation of the output signal by varying the temperature of the first radiation source and/or the temperature of the second radiation source, and detecting means for detecting a response signal.

Abstract: A probe assembly for examining a sample, the assembly including a probe, a fiber optic cable for communicating signals to and/or from the probe, an emitter for emitting radiation to irradiate the sample and an electro-magnetic radiation detector for detecting radiation which is transmitted or reflected from the sample. The emitter includes a frequency conversion member which emits radiation in response to being irradiated with input radiation which has a different frequency to that of the emitted radiation. At least one of the emitter or detector is located in the probe. The probe is particularly for use as an endoscope or for imaging teeth. The invention also extends to a method of imaging teeth, and apparatus for imaging diseased teeth, for example, teeth with caries or suffering from periodontal disease.

Abstract: A method for imaging a sample, the method comprising the steps of: (a) irradiating the surface of a sample with a source of coherent substantially continuous radiation with a frequency in the range 25 GHz to 100 THz; (b) detecting said radiation reflected from or transmitted by the sample; (c) providing and detecting a probe beam having a phase related to that of the radiation leaving the source; (d) analysing the detected radiation for at least one characteristic feature within the radiation and monitoring any change in phase of such at least one feature in order to derive structural information about the sample as a function of depth from the surface of the sample.

Abstract: An apparatus for investigating a sample comprising: a source of beam radiation; a detector for detecting a beam of radiation reflected by the sample and an optical subsystem for manipulating the beam between source and detector wherein the optical subsystem comprises a first optical element arranged in use to angularly deflect the source beam within a given solid angle and a second optical element arranged to focus the beam from the first optical element onto a substantially flat image plane and wherein radiation reflected by the sample passes back through the first and second optical elements to the detector.

Abstract: An apparatus for varying the path length of a beam of radiation, the apparatus comprising: an element (51) rotatably mounted about an axis, said element comprising two reflective surfaces in fixed relation to one another such that radiation may be reflected between said reflective surfaces and out of the element (51); and driving means (55) for rotatably oscillating said element about said axis.

Abstract: Apparatus and method for detecting an explosive material, involving irradiating an object with a continuous wave (CW) or pulsed beam of Terahertz radiation, preferably in the frequency range of 100 GHz to 100 THz and detecting radiation transmitted and/or reflected from the object. A spectrum is constructed from the detected radiation, which is indicative of a fundamental property of the explosive material. This constructed spectrum is compared with one or more known spectra of explosive materials to determine whether a likeness exists.

Abstract: In an apparatus and method for imaging a sample: a) the sample to be imaged is irradiated with pulsed electro-magnetic radiation with a plurality of frequencies in the range from 50 GHz to 84 THz; b) an area of the sample is subdivided into a two dimensional array of pixels, and radiation from each pixel is detected over a plurality of frequencies; and c) an image is generated from the radiation detected in step (b) preferably using a frequency or a selection of frequencies from the plurality of frequencies in the pulsed electro-magnetic radiation. The method can be used as a medical imaging technique and can be used to image cancer tumors.

Abstract: A method of investigating an object, comprising the steps of: (a) irradiating the object with an optically-generated pulse of electromagnetic radiation, said pulse having a plurality of frequencies in the range from 100 GHz to 100 THz; (b) detecting radiation transmitted and/or reflected from the object to obtain a time domain waveform; (c) repeating steps (a) and (b) for a plurality of points on the object and (d) combining data from step (c) to produce a time domain waveform for the object which has been averaged over the plurality of points.