Abstract: A method and apparatus for testing a paper of value, in particular for condition testing of a bank note, are proposed wherein the bank note is subjected both to dark-field measurement and to bright-field measurement. From comparison of the measuring results of dark-field measurement and bright-field measurement one can make a clear statement about whether a flaw, for example a hole, tear, etc., is present in the bank note in the tested area. The bright-field and dark-field measuring devices can be formed separately with one LED array and detector array in each case. However, preferred embodiments provide for either a common LED array with two detectors or two LED arrays with a common detector. If two LED arrays are used, the dark-field radiation source is preferably formed as an IR light source and the bright-field radiation source as a red-light radiation source in order to permit authenticity testing of the paper of value to be performed as well as condition testing thereof. (FIG.

Abstract: A method of improving spatial resolution of a pump-probe terahertz (THz) imaging system for producing an image of an object. The method provides a chopped optical gating beam focused on a semiconductive layer that is either part of the object or a discrete layer placed over the object. The gating beam is focused on a gating pulse focal spot having a diameter effective to cause measurable modulation in transmission of a THz beam through the semiconductive layer when the gating pulse is on as compared to when the gating pulse is off, creating alternating modulated THz beams for detection and processing. Systems for performing the method in transmission and reflection modes are also described.

Abstract: A method and infrared thermal imaging apparatus detects normal and angled cracks on or beneath a sample surface using infrared thermal imaging where the crack plane is perpendicular or angled to an imaged surface of the sample. A constant heating source is used for heating a section of the sample to produce a lateral heat transfer through the sample. An infrared camera is positioned near one side of the sample for receiving thermal image data resulting from the lateral heat transfer through the sample. A data acquisition and processing computer is used for acquiring and differentiation processing thermal image data from the infrared camera for generating two-dimensional first derivative and second derivative images to detect the normal and angled cracks.

Abstract: A smoke detector is shown in which blue light is directed through a scattering volume (9) from a radiation emitter (3) and infra-red radiation is also directed through the scattering volume (9) from an infra-red source (3A). Radiation forward-scattered by any particles in the scattering volume (9) is directed by a mirror (13) onto a photodiode (15) which produces an output to control means (16). The emitters (3,3A) are pulsed at different frequencies, enabling the control means (16) to produce separate signals (21,23) corresponding respectively to the scattered blue light and the scattered infra-red radiation. For smoke particles, significantly more blue light is scattered than infra-red radiation, but this is not so much the case for non-smoke particles. A comparator (25) takes the ratio of the two signals (21,23) to produce a smoke-dependent warning output.

Abstract: An invention is described, which uses terahertz radiation for chemical sensing and gas analysis. Relatively narrow-band THz radiation is generated by impinging an optical pulse train from a short-pulse laser source on a THz emitter. Coherent detection of the resulting THz radiation is accomplished by using a similar optical pulse train to activate the THz sensor. The invention is shown to detect and indicate various concentrations of water vapor in air. Optimal phase biasing conditions give maximum sensitivity to variations in concentration of the species under investigation.

Abstract: THz imaging apparatus and methods are provided for rapidly and effectively examining a region of interest to determine the presence of specified compositions. The apparatus includes means for generating electromagnetic radiation of a desired terahertz frequency suitable for the examination, and for rendering the radiation incident at the region of interest. Detector means are provided at a plurality of points in a plane spaced from the region of interest, for detecting the terahertz radiation reflected from or transmitted through the region. Means are provided for converting the detected terahertz radiation to an image of the region of interest from which the presence of the specified compositions are determinable.

Abstract: An apparatus for investigating a sample comprising a source of a beam of radiation, a detector for detecting a beam of radiation reflected by or transmitted through a sample to be imaged, an optical subsystem for manipulating the beam between the source and detector and means for translating the optical subsystem along a first translation axis relative to the source and detector to scan the beam across the sample, wherein the source and the detector are on opposite sides of the subsystem and the beam from the source and the beam reflected or transmitted each enter and exit the subsystem in a direction parallel to the first direction of translation. The apparatus is also suitable for maintaining the relative phase of two beams of radiation, during translation of an optical subsystem.

Abstract: The invention relates to methods of localizing a deviant region in a turbid medium. The invention also relates to devices for carrying out such methods. The methods can possibly be used in optical mammography where a breast of a female body is examined using light. Said methods produce images in which any deviations, for example tumors, can be clearly recognized. This is achieved inter alia by providing markers (10) in an image (9) of the turbid medium.

Abstract: An apparatus (295) using specular reflection spectroscopy to measure a temperature of a substrate (135). By reflecting light (100) from a substrate, the temperature of the substrate can be determined using the band-edge characteristics of the substrate. This in situ apparatus can be used as a feedback control in combination with a variable temperature substrate holder to more accurately control the processing conditions of the substrate. By utilizing a multiplicity of measurement sites, the variation of the temperature across the substrate can also be measured.

Abstract: A method and apparatus for calibrating an acoustic thermography system 10 and/or enhancing the flaw detection abilities of such a system is provided. The method allows applying a material (e.g., 103) to a specimen 12 undergoing acoustic thermography inspection. The material is thermally responsive to acoustic energy transmitted to the specimen by the acoustic thermography system. In one aspect thereof, a thermal response of the material applied to the specimen when subjected to acoustic energy is processed to determine whether the level of acoustic energy applied by the acoustic thermographic system appropriately meets a desired amount of acoustic energy for inspecting the specimen. In another aspect thereof, the thermal response of the specimen in combination with the applied material may be processed to determine whether certain types of flaws (e.g.

Abstract: In an infrared obstruction detection system, an apparatus is used to detect the presence of ambient light and initiate compensation to minimize the effects of the ambient light on the performance of the system. In one embodiment, the magnitude of the ambient light is measured and an offset proportional to that magnitude is fed to the obstruction detection system such that the data indicative of an obstacle are not obscured. In another embodiment, the apparatus continually monitors the effect of ambient light and adjusts the obstacle detection information during the changing states of the ambient light detected.

Abstract: In an apparatus for reading codes of a thermoluminescence detector, a housing including an optical unit is disposed on a base together with a disc-like magazine, which is rotatably supported adjacent the housing and provided with an annular array of recesses receiving the thermoluminescence detectors to be examined. The housing has a side opening through which the magazine extends into the housing, in which a light source is disposed for the homogeneous illumination of the thermoluminescence detectors from one side thereof, A CCD camera is disposed in the housing at the other side of the magazine for recording the illuminescence generated by the detectors when exposed to the light from the light source for determining the radiation exposure of thermoluminescence detectors.

Abstract: The invention relates to a method for determining any fluid mixture composition and for measuring material quantity by detecting light absorption, especially infrared light, emitted by an emitter (12.1, 12.2) in a fluid to be analyzed having non absorbed and non reflected components that are detected by a receptor (18.1, 18.2). According to said method, light is emitted directly from the emitter (12.1, 12.2) to the receptor (18.1, 18.2) through said fluid. Additionally, the light going through a channel (10, 16)before and/or after the fluid is dispersed at least once. The distance between emitter (12.1, 12.2) and receptor (18.1, 18.2) can be continuously altered. Electronic components are provided with a switch enabling to remove any interference light.

Abstract: An infrared absorption gauge includes a detector circuit including a detector for detecting electromagnetic radiation from a sample and for generating a signal representing the radiation received, and means for stabilizing a response characteristic of the detector to the radiation detected thereby, said stabilizing means having a GaAs diode for directing radiation at the detector and means for controlling the radiation source in dependence upon the signal generated by the detector. The stabilizing means thus acts as a negative feedback loop and seeks to maintain the overall illumination irradiating the detector (i.e. the combined illumination that is reflected back from the sample and that is emitted by the GaAs diode), at a substantially constant predetermined level, which tends to linearize and extend the frequency response of the detector to the radiation detected.

Abstract: A device for detecting properties of a moving web of paper, more specifically for production control in the paper making process, comprising an infrared lighting device suited for illuminating the web of paper with infrared light and a detector device for detecting light reflected or transmitted by the web of paper which is provided with a light input portion. The infrared lighting device is provided with a light source in the form of a long, rod-shaped infrared emitter, the light source being accommodated in a housing having a front plate facing the web of paper. An exit window, through which the light from the light source passes to impinge upon the web of paper, is tight-fittingly received in an aperture in the front plate.

Abstract: A method and apparatus for detecting, locating, isolating and controlling variations in the manufacturing process by transient thermography. A heat source (200) imparts heat to a surface which is radiated in the infrared region. Infrared sensors (204, 206, 208, 210) are coupled to a processor which tracks the physical characteristics of the sample, and provides feedback to a central process controller to make adjustments to the manufacturing process. The sample can be a continuous product such as a green powder metal sheet or tobacco product.

Abstract: An optical CT apparatus 10 is mainly composed of a container 12 filled with an optical interface member 20; a light-projecting section, comprising a light source 22 and an optical switch 24, for projecting light into the container 12; a light-detecting section, comprising photodetectors 30 and shutters 32, for detecting the light from the inside of the container 12; and an arithmetic/control section 14 for calculating a spatial distribution of absorption coefficient. The arithmetic/control section 14 has a function of determining a spatial distribution of a characteristic amount concerning a part of an object to be measured 200 according to a comparison of an optical intensity signal actually measured by each detector 30 in a state where the container 12 is filled with the optical interface member 20 with an optical signal actually measured by each detector 30 in a state where the optical interface member 20 is partly replaced by the part of object to be measured 200.

Abstract: A method for detecting defects in an optical device. The method includes obtaining an optical device that is a component of an optical communications system carrying information signals at a communications wavelength. Infrared light is applied to the optical device. The infrared light has a wavelength corresponding to the communications wavelength. An image of the optical device is obtained while the optical device is transmitting the infrared light. The image provides multidimensional data including positional values and intensity values. The image is then analyzed to detect defects in the optical device.

Abstract: A process and an apparatus preferably used during the photocagulation of the fundus of human eyes or animals measures density fluctuations caused by pulsed irradiation, such as a laser irradiation source, on a material. A wherein a measuring signal is acoustically or optically detected. The change of the intensity and/or of the time slope of the measuring signal resulting from the irradiation of a specific material point is detected. A linear thermo-elastic signal fraction is removed from the measuring signal.

Abstract: An infrared banknote acceptor for use to verify the authenticity of banknotes is constructed to include a housing, the housing having a base adapted to hold the banknote to be verified, a light source adapted to emit an infrared light beam onto the banknote carried on the base of the housing for verification, an image pickup adapted to receive infrared light reflected by the ink of the banknote carried on the base of the housing for verification and to convert received infrared light signal into video signal, and a display unit adapted to receive and display the video signal outputted from the image pickup.

Abstract: An input device for detecting input with respect to a reference plane. The input device includes one or more light sensors positioned to sense light at an acute angle with respect to the reference plane and for generating a signal indicative of sensed light, and a circuit responsive to said light sensor for determining a position of an object with respect to the reference plane.

Abstract: A system and method for using terahertz radiation to detect and monitor a substance undergoing a change in phase from a liquid phase to a solid phase or vice-versa is disclosed. By employing terahertz radiation in either the pulsed mode or in the continuous-wave (CW) mode, the system can non-invasively monitor these changes. The system uses the principle that matter in a liquid state will absorb and attenuate terahertz radiation to a larger degree than matter in a semisolid or solid state. Most terahertz radiation absorption occurs due to the rotational motions of molecules, i.e. either whole molecules or groups of atoms rotating about molecular bonds.

Abstract: A method and an apparatus for controlling a moisture profile of a paper web, in which the moisture profile of the paper web prior to drying is measured. The measurement is carried out with a measuring device, which measures a cross-direction profile of the web substantially simultaneously. On the basis of the measurement, the moisture profile of the paper web is controlled prior to drying the paper web.

Abstract: A method of the present invention includes exposing a structure to first electromagnetic radiation including at least one wavelength absorbed by a predetermined substance that is to be detected. Such substance can be water, a water-soluble substance, or fungi, the presence of which can be a significant problem in a structure such as a house or building. The method includes sensing second electromagnetic radiation from the structure, the second radiation based on the first radiation. The method also includes determining whether the substance is present in the structure, based on the sensed second radiation. If the substance to be detected is water and the determining step reveals a water-suspect area in the structure, the method can include testing the water-suspect area of the structure to determine whether water is present therein. If water is confirmed by the determination to be present in the structure, the method can include a step of determining the source of the water.

Abstract: A method of the present invention includes exposing a structure to first electromagnetic radiation including at least one wavelength absorbed by a predetermined substance that is to be detected. Such substance can be water, a water-soluble substance, or fungi, the presence of which can be a significant problem in a structure such as a house or building. The method includes sensing second electromagnetic radiation from the structure, the second radiation based on the first radiation. The method also includes determining whether the substance is present in the structure, based on the sensed second radiation. If the substance to be detected is water and the determining step reveals a water-suspect area in the structure, the method can include testing the water-suspect area of the structure to determine whether water is present therein. If water is confirmed by the determination to be present in the structure, the method can include a step of determining the source of the water.

Abstract: The invention relates to a sensor array for image recognition, comprising several optical sensor elements (R, G, B) of a first type that are disposed in the shape of a grid and react to light in the visible wavelength range, wherein additional sensor elements (IR) of a second type are provided in addition to the sensor elements (R, G, B) of the first type, which react to light in the invisible wavelength range.

Abstract: A method for monitoring a biological tissue includes illuminating the tissue, including a fluorophore, with a wavelength of light, the wavelength selected for exciting the fluorophore, determining a fluorescent emission of the fluorophore, the emission indicating the presence of the fluorophore, and correlating an emission of the fluorophore to an extent and degree of damage to the tissue. Damage to the tissue includes a breakdown of the fluorophore, resulting in a reduced level of emission. The fluorophore can include one of collagen and elastin. The fluorophore can include tryptophan, nicotinamide adenine dinucleotide, flavin and porphyrin. Correlating the emission of the fluorophore to the extent and degree of damage further includes processing a correlation of the emission over time, controlling the power of a laser welder based on the processed correlation, and preventing overheating of the tissue by the laser welder.

Abstract: An optical transmitting and receiving device with light-conducting receiver, which are arranged inside the housing, in front of a light-permeable cover between a transmitting unit and a receiving unit, so that the share of light reflected at the light-permeable cover of the transmitting unit is conducted to the receiving unit, thus making it possible to detect the operational readiness of the transmitting unit as well as the degree of soiling of the light-permeable cover.

Abstract: A fluidization level sensor and controller for use in a fluidized patient support surface has a controller coupled to a sensor and a compressor. The patient support surface contains a mass of granular particles housed in frame walls and supported by a diffuser. The compressor forces a fluid, typically air, into a plenum chamber and through the diffuser. The fluid flows through the mass of granular particles, causing the mass of granular particles to fluidize, and exits through a fluid permeable sheet. The fluidization level sensor produces an output signal proportional to the fluidization level of the mass of granular particles, and provides this output signal to the controller. The controller generates a compressor control signal in response to the output of fluidization level sensor, which in turn adjusts the compressor to maintain a substantially constant fluidization level.

Abstract: This invention teaches a method to identify cellular abnormalities which are associated with disease states. The method utilizes infrared (IR) spectra of cell samples which are dried on an infrared-transparent matrix and scanned at the frequency range from 3000-950 cm−1. The identification of samples is based on establishing a reference using a representative set of spectra of normal and/or diseased specimens. During the reference assembly process, multivariate techniques such as Principal Component Analysis (PCA) and/or Partial Least Squares (PLS) are used. PCA and PLS reduce the data based on maximum variations between the spectra, and generate clusters in a multidimensional space representing the different populations. The utilization of Mahalinobis distances, or linear regression (e.g., Principle Component Regression on the reduced data from PCA) form the basis for the discrimination.

Abstract: An image processing method is provided for obtaining a non-deteriorated pixel value as a pixel value of a pixel free from a defect such as a scar or dust from non-visible beam image information obtained from a defective recording medium having the scar or dust.

Abstract: A method of the present invention includes exposing a structure to first electromagnetic radiation including at least one wavelength absorbed by a predetermined substance that is to be detected. Such substance can be water, a water-soluble substance, or fungi, the presence of which can be a significant problem in a structure such as a house or building. The method includes sensing second electromagnetic radiation from the structure, the second radiation based on the first radiation. The method also includes determining whether the substance is present in the structure, based on the sensed second radiation. If the substance to be detected is water and the determining step reveals a water-suspect area in the structure, the method can include testing the water-suspect area of the structure to determine whether water is present therein. If water is confirmed by the determination to be present in the structure, the method can include a step of determining the source of the water.

Abstract: An apparatus and method for investigating a sample, the apparatus comprising: means (61) for irradiating the sample (21) with a first beam of electromagnetic radiation configured to excite an optically non-linear process within the sample; means (61) for irradiating the sample with a second beam of electromagnetic radiation; and a detector (41) for detecting a change the second beam after it has been reflected from or transmitted through the sample. If the optically non-linear process is a second order process, the detector could be used to detect a change in the polarisation of the second beam. Apparatus and method find application of samples with terahertz (THZ) radiation locally generated and detected within the sample.

Abstract: A detection system for identifying surface irregularities such as cracks, pits, scratches and holes in a part that is made of a material having a relatively high reflectivity and a relatively low emissivity such as titanium, aluminum, and silicon (such as silicon solar panels). A laser source generates a laser beam having a diameter that is approximately 50 microns or less. A scanning device scans the laser beam across the surface of the part. A surface irregularity radiates energy from said laser beam. An infrared receiver is directed at the surface of the part. The infrared receiver generates an infrared signal of the surface. A display that is connected to the infrared receiver displays the infrared signal to identify surface irregularities. Preferably, the infrared receiver is oriented at a first angle relative to a line perpendicular to the surface of the part. The first angle is preferably greater than 20 degrees and less than 30 degrees.

Abstract: Optical transmitter 2 is equipped with transmitted pulse modulator 23. at which a plurality of optical transmission patterns have previously been stored. The respective stored optical transmission patterns have mutually different ratios between infrared pulse ON times and OFF times. Optical output of infrared signal(s) transmitted from optical transmitter 2 is made variable as a result of the fact that infrared pulse(s) output during infrared output period(s) is or are output in accordance with an optical transmission pattern selected from among the plurality of optical transmission patterns.

Abstract: A spectral reflectance sensor including: a light source for emitting a modulated beam of red light; a light source for emitting a modulated beam of near infrared light; a receiver for receiving reflected light produced by either the red source or the near infrared source; a receiver for receiving incident light from either the red source or the infrared source; a signal conditioner responsive to the modulation such that the signals produced by the receivers in response to reflected and incident light from the source can be discriminated from signals produced by ambient light; and a microprocessor having an input such that the microprocessor can determine the intensities of incident red light, reflected red light; incident near infrared light; and reflected near infrared light. From these intensities, and by knowing the growing days since emergence or planting, the sensor can calculate the mid-growing season nitrogen fertilizer requirements of a plant.

Abstract: A light detecting and ranging system and method for detecting airborne agents in which the system includes a laser which provides laser pulses of at least two wavelengths, a transmitter which transmits the laser pulses, a receiver which receives both elastically backscattered signals from airborne agents and fluorescence signals from the airborne agents, a common telescope which both focuses a laser beam transmission of the laser pulse from the transmitter to a far field and receives the elastically backscattered signals and the fluorescence signals from the far field, a digital detection system having at least one of a backscatter optical detector which detects the elastically backscattered signals and a fluorescence optical detector which detects the fluorescence signals from the airborne agents.

Abstract: An apparatus for reading images of a photographic film disposed on an image reading optical path, with a light source (31a) for emitting visible light and infrared light into the image reading optical path to irradiate the photographic film, and a zoom lens unit (32a) for the visible light and infrared light irradiating the photographic film. A visible light sensor and an infrared light sensor are disposed separately for detecting a visible image based on the visible light from the zoom lens unit, and for detecting an infrared image based on the infrared light from the zoom lens unit, respectively. A focal position varying transparent element (FT) is provided for shifting a focal position of the zoom lens unit along an optical axis. The transparent element is movable to and from a position between the zoom lens unit and infrared light sensor to correct variations in the focal position occurring with variations in magnification of the zoom lens unit.

Abstract: The invention relates to a device for detecting properties of a moving web of paper, more specifically for production control in the paper making process, with an infrared lighting device suited for illuminating the web of paper with infrared light and provided with a light exit portion, with a detector device for detecting infrared light reflected or transmitted by the web of paper which is provided with a light input portion and with a housing a) which is arranged in immediate proximity to the paper web, b) which is provided with a front face facing the web of paper and c) which accommodates the light exit portion and/or the light input portion provided with optical fibers. A plurality of n spherical lenses is arranged in a sealed manner in the front face, said spherical lenses being each optically coupled to an allocated optical fiber within the housing, said spherical lenses constituting, together with the corresponding optical fibers, the light exit portion and/or the light input portion.

Abstract: Method for identification of plastic materials of interest by spectroscopic measurements, comprising the steps of measuring a sample and providing a sample spectrum; providing reference spectra for a given group of reference materials of interest, determining spectral distances between sample spectrum and reference spectra, material identification by associating the sample to the material having the reference spectrum with the smallest spectral distance to the sample spectrum. In this method a multi-level measurement is conducted, wherein in each level the number of possible materials is further limited. In a first level at least 2 sub-groups and in all levels starting with a second level at least one sub-group of possible materials are defined, wherein one sub-group in the first level comprises all possible materials that are easily distinguishable and at least one further sub-group in the first level comprises materials that are difficult to distinguish from each other.

Abstract: A method and an apparatus for nondestructively detecting the orientation of anisotropic molecules in thin films and in molecular layers in general. The present invention is based on a single measurement of the non-polarized photoluminescence spectrum, in order to determine whether the molecules are orientated at right angles or parallel to the surface of the molecular layer, fabricated with any technique. The method is fast and noninvasive and can also allow to observe noninterferingly in real time during growth the orientation of the molecules in the film. The result of this real-time observation can be used to optimize the growth conditions of the film in order to achieve the intended molecular orientation.

Abstract: The present invention relates to an apparatus for detecting an object-to-be-printed and aims at providing an apparatus for detecting an object-to-be-printed which is capable of discriminating whether the object-to-be-printed is plain paper or special paper. The apparatus includes an infrared sensor for detecting infrared rays 4 radiated by heating the object-to-be-printed 1 with heating means 2 and is capable of discriminating whether the object-to-be-printed is plain paper or special paper.

Abstract: A process including: magnetically energizing susceptible magnetic particles; and accumulating the resulting terahertz lasing mode output of the particles.

Abstract: A method and apparatus for detecting and removing water from a surface of a moving metal sheet in continuous treatment line to prevent the formation of water stains thereon. A selected surface area of the moving metal sheet is illuminated with infrared radiation having a wavelength substantially absorbed by water, and an optical sensor system is employed to view images reflected off the selected surface area. An optical bandpass filter limits transmission of infrared light to within a specific range of wavelengths known to be strongly absorbed by water. The sensor assembly produces a signal representative of the intensity of the reflected light. If the intensity signal is lower than a predetermined level, water is detected and the signal may be used to trigger a control device that sounds alarms, records the event, or otherwise controls the environment of the object so that detected water may be removed to prevent the formation of water stains.

Abstract: A method of determining at least one characteristic of one or more security documents such as banknotes, each security document including a sheet-like substrate of plastics material and opacifying layers applied to opposing faces of the substrate, the method comprising the steps of: (a) projecting radiation from a radiation source into the substrate of each security document for propagation therein, the opacifying layers acting to guide the projecting radiation within the substrate; (b) detecting a radiation emission of the substrate of each security document, the radiation emission resulting from the propagated radiation; and (c) analysing one or more characteristics of the radiation emission.

Abstract: A detection system for identifying surface irregularities such as cracks, pits, scratches and holes in a part that is made of a material having a relatively high reflectivity and a relatively low emissivity such as titanium, aluminum, and silicon (such as silicon solar panels). A laser source generates a laser beam having a diameter that is approximately 50 microns or less. A scanning device scans the laser beam across the surface of the part. A surface irregularity radiates energy from said laser beam. An infrared receiver is directed at the surface of the part. The infrared receiver generates an infrared signal of the surface. A display that is connected to the infrared receiver displays the infrared signal to identify surface irregularities. Preferably, the infrared receiver is oriented at a first angle relative to a line perpendicular to the surface of the part. The first angle is preferably greater than 20 degrees and less than 30 degrees.

Abstract: A microwave-enhanced infrared thermography technique for detecting buried objects exploits varying phase shifts experienced by different-frequency microwave signals reflected from objects back toward the surface, the phase shifts resulting in different interference patterns and therefore different temperature distribution patterns near the surface. Respective infrared images of an area are captured prior to microwave heating, after a first heating with a first frequency, and after heating with a second frequency different from the first. Pairs of the images are subtracted to form temperature rise images showing patterns of temperature rise in the two cycles, and the temperature rise images are subtracted to form a difference image which is analyzed to identify characteristics indicating the presence of buried objects.

Abstract: The invention is based on the discovery that indirect, three-dimensional images of features within turbid or dense samples can be reconstructed based on principles of radiative transport to provide higher resolution images than diffuse imaging methods, while enabling penetration depths significantly greater than microscopic imaging methods. The new indirect mode imaging methods enable one to “see” into turbid or dense samples, such as tissue in living animals or humans, ceramics, plastics, liquids, and other materials, to a depth of 50 &mgr;m to 10 mm or more, with higher resolution than diffuse imaging methods.

Abstract: A device for detecting properties of a moving web of paper, more specifically for production control in the paper making process, comprising an infrared lighting device suited for illuminating the web of paper with infrared light and a detector device for detecting light reflected or transmitted by the web of paper which is provided with a light input portion. The infrared lighting device is provided with a light source in the form of a long, rod-shaped infrared emitter, the light source being accommodated in a housing having a front plate facing the web of paper. An exit window, through which the light from the light source passes to impinge upon the web of paper, is tight-fittingly received in an aperture in the front plate.

Abstract: A spectroscopic method for characterizing a sample including: positioning the sample adjacent to a non-centrosymmetric material; directing at least one temporal pulse of coherent EM radiation into the non-centrosymmetric material to generate a polariton therein and cause EM radiation from the polariton to propagate into the sample, wherein the polariton has a frequency less than or equal to the bandwidth of the pulse; and measuring a response of the sample to the EM radiation from the polariton.