Abstract: 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.

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 method for analysing a sample comprising a layer having a first interface and a second interface, the method comprising: Irradiating the sample with a pulse of terahertz radiation, said pulse comprising a plurality of frequencies in the range from 0.

Abstract: 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.

Abstract: A method and apparatus is provided for determining the thickness of coating layers of a curved surface when examining the surface with terahertz radiation. The method involves measuring detected reflected radiation and applies a correction factor to obtain the thicknesses of the layers. This addresses the problem of compensating for the curvature of the surface when determining coating thickness.

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 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.

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 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.

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 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.

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 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.

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 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 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.

Abstract: A method for determining the thickness of a plurality of coating layers, the method comprising: performing a calibration analysis on calibration data to determine initial values and search limits of optical parameters of said plurality of coating layers, irradiating the said plurality of layers with a pulse of THz radiation, said pulse comprising a plurality of frequencies in the range from 0.01 THz to 10 THz; detecting the reflected radiation to produce a sample response said sample response being derived from the reflected radiation; producing a synthesised waveform using the optical parameters and predetermined initial thicknesses of said layers; and varying said thicknesses and varying said optical parameters within the said search limits to minimise the error measured between the sample response and the synthesised waveform; and outputting the thicknesses of the layers.

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 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.