摘要:
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 the pulsed source; a second photoconductive element configured to receive a pulse; and 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. At least one of the first and second photoconductive elements is provided on a different substrate to that of the transmission line arrangement.
摘要:
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.
摘要:
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.
摘要:
A method for determining the thickness of a plurality of coating layers. The method comprises the steps of performing a calibration analysis on calibration data to determine initial values and search limits of optical parameters of the plurality of coating layers, irradiating the plurality of layers with a pulse of THz radiation in the range from 0.01 THz to 10 THz, detecting the reflected radiation to produce a sample response derived from the reflected radiation, producing a synthesized waveform using the optical parameters and predetermined initial thicknesses of the layers, varying the thicknesses and the optical parameters within the search limits to minimize the error measured between the sample response and the synthesized waveform, and outputting the thicknesses of the layers.
摘要:
A reflectometer for allowing a test of a device. The reflectometer comprises a source of pulsed radiation, a first photoconductive element configured to output a pulse in response to irradiation from the 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 the transmission line configured to match the impedance of the transmission line.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
An antenna comprising a photoconductive material (61) and a plurality of spaced apart electrodes (69, 71) provided on said photoconductive material (61), each electrode (69, 71) having at least one facing edge which faces a facing edge of an adjacent electrode, a physical barrier (67) being provided abutting a facing edge of at least one electrode (69, 71), said barrier (67) extending to at least the full height of said facing edge.