Abstract: A modular hyperspectral thermal camera that combines a wide field-of-view with a low erroneous recognition rate is described. The modular hyperspectral thermal camera provides such low erroneous recognition rates without any requirement for cryogenically cooling the associated optical components. The modular nature of the hyperspectral thermal camera permits easy exchange of the optical components and so provides a device that is easily calibrated and varied in resolution. In addition the modular nature allows the hyperspectral thermal camera to be readily converted to a broad band thermal camera, a full field spectrograph or a thermal bandpass filter camera, as required.

Abstract: A smoke detector includes a smoke detection chamber containing a white light LED and a light detector. The light detector detects light within at least two distinct optical wavelength bands, and generates respective signals indicative of the intensities of the detected light. An analyzer determines, based on the measured light intensities of the different wavelength bands, whether a dangerous smoke/fire condition is present.

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: A GFCR system receives light from a scene of interest and focuses it to form an image. Light associated with a selected field-of-view of the image is confined to a spectral band absorbable by a gas of interest and is split into first and second paths. A region that does not substantially interfere with the spectral band is disposed in the first path. A first two-dimensional array of optical detection elements is disposed in the region along with a first diffuser. Disposed in the second path are a gas cell filled with the gas of interest, a second two-dimensional array of optical detection elements, and a second diffuser. The first and second optical arrays generate output signals that are summed to form corresponding first and second sums. A difference between the first and second sums is generated and normalized as a direct measure of the gas of interest.

Abstract: A package including a container and closure, and a method of authenticating same. In the package or a portion thereof, a marker material is dispersed into a base material and can be detected in the aftermarket by absorption spectroscopy to establish the authenticity of a product contained in the package.

Abstract: A method for producing stimulated emission of gamma radiation comprising: 1] providing at least first and second gamma-radiation sources, both sources being in recoil-free first-excited nuclear levels and the second source being in resonance with the first source and the gamma radiation from the first source being incident on the second source, 2] during the lifetime of its excited state, abruptly moving the first source through a distance equal to ½ the wavelength of the radiation emitted therefrom, thereby inducing a ?-phase-shift gamma radiation transparency in the second source whereby the ?-phase-shifted gamma radiation stimulates the excited nuclear resonant state of the second source to emit gamma radiation.

Abstract: An entrance aperture of a GFCR system receives light from a scene of interest. The light is focused to form an image at a focal plane. Light associated with a selected field-of-view of the image at the focal plane is then confined to a spectral band at which a gas of interest absorbs. The confined light is split into first and second paths. A calibrating light is selectively produced from within the optical train at the focal plane. A portion of the calibrating light traverses each of the first and second paths. A region that is substantially non-interfering with respect to the spectral band is disposed in the first path. A gas cell filled with the gas of interest is disposed in the second path. The light passed through the region and through the gas cell is independently detected and used to generate output signals indicative of the light so-detected.

Abstract: An infrared refractive lens triplet having color correction properties for radiation within the 3 to 12 micrometer spectral band for use with a quantum well detector for simultaneous dual band imagery. In certain embodiments of the invention, two widely spaced triplets form a Petzval-type objective lens. Each lens triplet is made up of a negative zinc sulfide lens, a positive zinc selenide lens, and a negative gallium arsenide lens coaxially positioned along a chief ray of the lens system.

Abstract: A collision prevention detector (22), and a method therefor, to be mounted on a vehicle (10), transmits a sequence of transmissions of IR signals. The signals are transmitted in sequences alternating between at least one at the right and to the left positioned LED (24, 26, 34, 36), when both signals provide a return/reflected signal to IR-receiver an object (12) is determined as present within the area/zone from the point where the transmitted signals intersect/cross. Sequencing of signals makes it possible to position a return signal from an object (12), as one of the signals has to confirm the other signal to provide a warning signal. Moreover, a first set of LED's detects objects in a near-field zone (40) of the vehicle, and a second set detects objects beyond the first field in a far-field zone (42), whereby at least two sets of the LED's are positioned to the right and to the left.

Abstract: A photodetector having sensitivity in both an infrared and an ultraviolet band is provided. The photodetector is formed on a single chip and is designed to be blind to solar or visible radiation. Structures disclosed allow fast and efficient detection of signals with high spatial and temporal resolution. Such sensors may be used for multi-pixel focal arrays and applied for fire detection applications, various space- and military-related applications and other applications.

Abstract: One device embodiment includes a device for filtering radiation from a target region in multiple spectral bands. The device includes a number of optical quantum dot filters, each having a particular pass-through wavelength range, positioned on a rotatable disk.

Abstract: An IR imaging system includes a lens module and an imaging module coupled to the lens module. The lens module includes a barrel defining a through hole, at least one lens received in the through hole and an IR bandpass filter received in the barrel and configured for filtering out visible light. The imaging module includes a housing and an IR image sensor received in the housing. The IR imaging system can prevent IR image sensors being affected by visible light.

Abstract: Systems and methods for providing a wide angle multi-color infrared (IR) optical system are disclosed. In one embodiment, a system is provided that comprises a negative lens configured to receive an incoming light beam scene over a wide FOV and a beam splitter configured to receive incoming light beam associated with the incoming light beam scene from the negative lens and to provide light beams of a first color to a first channel and to provide light beams of a second color to a second channel. The system further comprises a first positive lens assembly arranged to focus light beams of the first color received from the beam splitter on a first image detector, and a second positive lens assembly arranged to focus light beams of the second color received from the beam splitter on a second image detector.

Abstract: An IR imaging system includes a lens module and an imaging module coupled to the lens module. The lens module includes a barrel defining a through hole, at least one lens received in the through hole and an IR bandpass filter received in the barrel and configured for filtering out visible light. The imaging module includes a housing and an IR image sensor received in the housing. The IR imaging system can prevent IR image sensors being affected by visible light.

Abstract: The invention provides a sensor element formed in a first substrate and at least one optical element formed in a second substrate, the first and second substrates being configured relative to one another such that the second substrate forms a cap over the at least one sensor element, the at least one optical element being configured to guide incident radiation on the cap to the at least one sensor element.

Abstract: An optical analysis system utilizing transmission spectroscopy for analyzing liquids and solids includes a source of optical energy, a sample, a movable optical energy transmission window, a fixed optical energy transmission window, and a detection system. The fixed transmission window remains fixed relative to the source of optical energy. The sample is selectively positioned between the movable and fixed optical energy transmission windows for analyzing the sample. The optical energy is transmitted through one of the windows, the sample, and the other window to obtain encoded optical energy as a result of transmitting the optical energy through the sample. A detection system receives the encoded optical energy for analysis. The movable optical energy transmission window is selectively movable relative to the fixed optical energy transmission window to repeatedly and precisely align and make readily accessible both windows and the sample.

Abstract: A sensor for measuring at least selected component in a composition can include: (a) a broadband light source, (b) an acousto-optic tunable filter (AOTF), (c) means for generating a beam of light from the light source and directing the beam of light at the AOTF wherein the AOTF is tuned to pass detection light having a desired wavelength range to detect the presence of the at least one component in the composition, (d) means for directing the detection light of known wavelength to the composition, (e) detection means for receiving light that emerges from the composition, and (f) a control signal generator configured to provide the AOTF with at least one desired wavelength range that is characteristic of the least one component in the composition. As an example, the sensor can be used to measure the thickness of optically transparent films.

Abstract: A chemical imaging system is provided which uses a near infrared radiation microscope. The system includes an illumination source which illuminates an area of a sample using light in the near infrared radiation wavelength and light in the visible wavelength. A multitude of spatially resolved spectra of transmitted, reflected, emitted or scattered near infrared wavelength radiation light from the illuminated area of the sample is collected and a collimated beam is produced therefrom. A near infrared imaging spectrometer is provided for selecting a near infrared radiation image of the collimated beam. The filtered images are collected by a detector for further processing. The visible wavelength light from the illuminated area of the sample is simultaneously detected providing for the simultaneous visible and near infrared chemical imaging analysis of the sample. Two efficient means for performing three dimensional near infrared chemical imaging microscopy are provided.

Abstract: Methods for determining corrosion products on a substrate are disclosed. In one embodiment, a non-destructive method for determining an amount of corrosion product on a metallic substrate includes non-destructively determining a value Ia of infrared energy absorbed in a corrosion product on a metallic substrate; and correlating the value Ia of the infrared energy absorbed to an amount of the corrosion product.

Abstract: An infrared gas detector for detecting a density of a sample gas includes an infrared light sensor for detecting the density of the sample gas under an influence of water vapor based on an intensity of received infrared light of a specific wavelength, and a humidity sensor for detecting an absolute humidity of the water vapor in the sample gas based on an intensity of the received infrared light of the specific wavelength. The density of the sample gas is determined by correcting for the influence of the water vapor included therein based on the absolute humidity in the sample gas detected by the humidity sensor.

Abstract: A method apparatus for sensing gases using a semiconductor diode laser spectrometer, the method comprising: introducing a sample gas into a non-resonant optical cell (17); applying a step function electrical pulse (19) to a semiconductor diode laser (20) to cause the laser (20) to output a continuous wavelength chirp for injecting (16a) into the optical cell (17); injecting (16a) the wavelength chirp into the optical cell (17); using the wavelength variation provided by the wavelength chirp as a wavelength scan, and detecting (23) light emitted from the cell (17), wherein a chirp rate is selected to substantially prevent light interference occurring in the optical cell (17).

Abstract: There is a need for a detection device which has high photoreceptive sensitivity in a generally wide frequency region including the infrared region. Therefore, in the present invention, by utilizing a phenomenon in which electric field strength is enhanced by surface plasmon resonance in a negative dielectric constant medium, a detection device is provided which has an electromagnetic wave detection portion disposed at a position where the electric field strength is large.

Abstract: A chemical imaging system is provided which uses a near infrared radiation microscope. The system includes an illumination source which illuminates an area of a sample using light in the near infrared radiation wavelength and light in the visible wavelength. A multitude of spatially resolved spectra of transmitted, reflected, emitted or scattered near infrared wavelength radiation light from the illuminated area of the sample is collected and a collimated beam is produced therefrom. A near infrared imaging spectrometer is provided for selecting a near infrared radiation image of the collimated beam. The filtered images are collected by a detector for further processing. The visible wavelength light from the illuminated area of the sample is simultaneously detected providing for the simultaneous visible and near infrared chemical imaging analysis of the sample. Two efficient means for performing three dimensional near infrared chemical imaging microscopy are provided.

Abstract: A level sensor for a lithographic projection apparatus includes a light source configured to direct light onto a substrate to be measured, a detector configured to detect light reflected from the substrate, and a processor configured to calculate a difference between measurements made with the filter in the first configuration and in the second configuration. The sensor is adjustable between a first configuration, in which the light is given a first property, and a second configuration, in which the light is given a second property. The sensor may include a polarizing filter, such that the first and second properties are different polarization states.

Abstract: A system and method for detecting radiation indicative of fire, such as forest fire. In one embodiment, a threshold energy level is determined based on ambient sensor conditions. A sensor unit may be setup to scan a predetermined area for electromagnetic radiation. Any detected electromagnetic radiation may then be band pass filtered to a wavelength range centered about a predetermined frequency associated with the presence of fire. The resulting energy level signal may then be further filter to pass only those signals which exhibit a “flicker” frequency. If the resulting filtered signal exceeds the threshold signal, a fire notification signal may then be generated.

Abstract: The the thickness of an opaque coating may be measured using near-infrared absorbance. One measurement method includes transmitting the near-infrared radiation towards the opaque material and determining relative absorbance levels over a range of near-infrared wavelengths. Absorbance wavelengths having relatively high absorbance and relatively low absorbance are then identified and selected. The selected wavelength values are then correlated with known material thicknesses.

Abstract: This invention relates to a method and apparatus for improved process control in combustion applications, and particularly those relating to the steelmaking industry. An apparatus is provided for process control in a combustion application comprising a laser to transmit a near-infrared laser beam through off-gas produced by the combustion application, a detector to detect the transmitted laser beam and convert the detected laser beam to an electrical signal, and a control system for providing adjustment of select inputs to the combustion application in response to the electrical signal from the detector. The method of this invention comprises transmitting a near-infrared laser beam through off-gas produced by the combustion application, detecting the transmitted laser beam, and adjusting select inputs of the combustion application in response to the detected transmitted laser beam.

Abstract: A fire detector and method for generating an alarm signal in response to a fire uses an NDIR CO2 sensor to generate a detector signal based upon a 15? absorption band of CO2 and generates an alarm signal when a signal processor receives the detector signal and a preselected criterion is met that is indicative of the onset of a fire based upon an analysis of the detector signal using a detection algorithm that relies upon a trending pattern of the detector signal such as recognizing a substantial drop in the detector signal strength. The NDIR CO2 sensor can also generate a reference detector signal based upon a 9.0? neutral band with a FWHM=0.5? while the signal processor utilizes a detection algorithm that is based upon a synchronized output signal representative of CO2 concentration to generate an alarm signal when a preselected criterion indicative of the onset of a fire is met.

Abstract: A fire detector with a passive CO2 sensor generates a detector signal based upon a 15? absorption band of CO2 and a signal processor generates an alarm signal when a preselected criterion is met. The passive CO2 sensor has a passive infrared source with a source temperature, a waveguide sample chamber with a gas medium temperature (which is less than the source temperature), a heat exchanger (that reduces the temperature of CO2 gas as it passes into the waveguide sample chamber and may be thermally coupled to the sample chamber) and an infrared detector assembly with a detector temperature (which is less than the source temperature). An exterior surface of the passive infrared source has a high emissivity while the detector assembly and the sample chamber (which can be thermally coupled to each other but not the passive infrared source) have a low emissivity.

Abstract: A fire detector and method for detecting fires uses a passive NDIR sensor that generates a detector signal based upon either a 15? absorption band of CO2 or a 6.27? absorption band of H2O and a signal processor which receives the detector signal and generates an alarm signal when a preselected criterion is met. The NDIR sensor relies upon a passive infrared source (such as a very thin film of black plastic material) with a high emissivity (e.g., approximately 1.0), a sample chamber with a low emissivity (e.g., approximately 0.03) thermally decoupled from the passive infrared source and an infrared detector located in a detector assembly thermally coupled to the sample chamber while a heat exchanger is thermally coupled to the sample chamber.

Abstract: A portable radiation detector using a high-purity germanium crystal as the sensing device. The crystal is fabricated such that it exhibits a length to width ratio greater than 1:1 and is oriented within the detector to receive radiation along the width of said crystal. The crystal is located within a container pressurized with ultra-pure nitrogen, and the container is located within a cryostat under vacuum.

Abstract: The present invention discloses a light source (10) for the illumination of microscopic specimens. The invention also discloses a scanning microscope system that possesses a light source (10). The light source (10) emits a combined light beam that is emitted by a first laser (4) and a second laser (6). In the combined light beam, the light of the first laser (4) is synchronized with the light of the second laser (6).

Abstract: The present invention relates to an instrument for measuring in relatively short periods of time concentrations of constituents in optically dense materials using the spectra near infrared radiation transmitted through thick samples of the material while the material is either stationary or flowing. The invention uses a broadband incandescent intensity stabilized light source combined with collimating optics to transmit a parallel beam of light through the material under test. The light transmitted through the material is then collected by a focusing lens and imaged onto a rectangular entrance slit of a special purpose spectrometer. This spectrometer has no moving parts and employs a fixed diffraction grating to physically spread the image of the entrance slit into a continuous range of wavelengths. A portion of the diffracted slit images covering the selected portion of the near infrared range is focused onto an array of individual rectangular photodiodes.

Abstract: A process and an apparatus are useful for identifying articles which are at least partly made from at least one polymer. The process and apparatus use an optical spectrometer and a transport system, whereby the articles to be identified are moved by the transport system past the optical spectrometer, where they are irradiated, response measured and analyzed. An external reference object is also transported, by the transport system, past the optical spectrometer such that it becomes possible to use the measured response for the reference object to identify, with greater accuracy, the articles to be identified.

Abstract: Rapid spectrum assay of multiple samples with infrared light is made possible by devices and methods that increase total light throughput. Multiple wavelength scan with Fourier analysis is combined with large numbers of sample wells located within infrared light compatible solid materials. In particular, very large scale measurement devices and systems for their use are fabricated from lithography and other techniques used for semiconductor processing.

Abstract: A method and apparatus for monitoring the flue gases of a furnace combustion process is disclosed. A by-pass circuit that communicates a sample of flue gases to be monitored from a furnace, through a measurement chamber and back to the furnace or furnace exhaust duct is provided. The by-pass circuit has a gas sampling probe with a fume inlet opening, the probe being positioned for withdrawing the sample to be monitored and transmitting it through the by-pass circuit. A measurement device is positioned in the measurement chamber and comprises an in situ optical device which provides real-time measurement of targeted flue gas species concentrations.

Abstract: A method for measuring a concentration of a hydroperoxide of an alkylaromatic hydrocarbon in a process stream comprises immersing a probe into the process stream; wherein the probe is coupled to a spectrometer; collecting absorption data with the spectrometer at a wavelength of 13,000 cm?1 to 4,000 cm?1; and calculating a concentration of the hydroperoxide of the alkylaromatic hydrocarbon in the process stream. In another embodiment, samples are withdrawn from the process stream and analyzed spectrometrically to determine the concentration of the hydroperoxide of the alkylaromatic hydrocarbon in the sample.

Abstract: This invention relates to a real-time infrared chemical imaging spectroscopic apparatus, including a light source for generating infrared radiation. A test sample absorbs a narrow-bandwidth infrared radiation as a result of a monochromator dispersing the infrared radiation and emits thermal radiation. IR camera collects the thermal radiation to form an image. As such, the present invention inspects the test sample in real time without a huge amount of complicated computation. Thus, the efficiency of inspection is increased and the optical design of the apparatus is more compact.

Abstract: A portable system for non-destructively measuring amount of coating on a metallic substrate based upon infrared absorbance includes a portable, hand-held measurement unit housed in a pistol-gripped case and an optical sensing unit that has an infrared source and a detector. The infrared source is configured to transmit infrared energy toward a metallic substrate having a coating thereon. The infrared energy passes through the coating, reflects off a surface of the substrate, passes back through the coating, and is detected by the detector. A processor correlates amount of infrared absorbance in the coating to amount of the coating. A base unit holds the hand-held measurement when not in use and charges a battery of the hand-held measurement unit. The base unit includes connectors for uploading and downloading data from and to the hand-held measurement unit and for communicating with an optional host computer.

Abstract: A two band imaging system having two focal plane array detectors, a beam splitter, and an enclosure. The beam splitter disposed within the system at an angle to the optical axis such that light entering the system is split and is simultaneously directed to each of the two focal plane array detectors. The two focal plane array detectors and beam splitter are disposed within the enclosure.

Abstract: A method is provided for predicting the durability of a composite structure, such as a composite polymeric coating. The method includes obtaining a sample of a first (reference) composite structure and analyzing at least one layer of the structure for indications of degradation. The sample can be obtained by low angle microtomy. Degradation values and a degradation slope of the first composite structure can be defined. One or more degradation values for a second composite structure can be obtained and the durability of the second composite structure can be predicted by comparing the degradation slope of the second composite structure to the degradation slope of the first composite structure.

Abstract: A method for optical detection of characteristic quantities of the wavelength-dependent behavior of an illuminated specimen, such as the emission behavior and/or absorption behavior, preferably the fluorescence and/or enzyme fluorescence comprises determining at least one spectral centroid and/or a maximum of the emission radiation and/or of the absorbed radiation. An arrangement for performing the method is disclosed.

Abstract: A method and apparatus are provided for in situ monitoring and analyzing of process parameters for semiconductor fabrication processes including cleaning semiconductor wafers utilizing a supercritical fluid or a high pressure liquid such as CO2. The method and apparatus utilize a spectrometer having a reflective mirror proximate the vessel holding the high pressure fluid. NIR radiation transmitted into the vessel through a window and out of the vessel through an opposed window is reflected and detected and measured and the composition of the fluid in the pressure vessel is determined allowing the user to control process parameters based on the measured composition.

Abstract: An analyte detection system non-invasively determines the concentration of an analyte in a sample generating a sample infrared signal indicative of the concentration of the analyte in the sample. The detection system includes a window assembly for receiving the sample infrared signal. The window assembly is adapted to allow the sample infrared signal to transmit therethrough, and generates a window infrared signal. The detection system further includes at least one detector configured to receive both the window infrared signal and the sample infrared signal transmitted through the window assembly. The detector is further adapted to generate a detector signal in response thereto. The detection system further includes a correction module configured to generate a corrected detector signal indicative of the concentration of the analyte in the sample.

Abstract: A method for spatially resolving flame temperatures in which a temperature-dependent wavelength region of a molecule radical spectrum and a normalization wavelength region of the molecule radical spectrum suitable for normalizing spectral data are identified. An algorithm based upon a relationship between a temperature-dependent intensity range within the temperature-dependent wavelength region at a plurality of temperatures and a normalized intensity range within the normalization wavelength region is formulated. Flame spectral data from a flame is obtained and the algorithm is applied to the flame spectral data, resulting in generation of a flame temperature profile of the flame.

Abstract: An apparatus and a method are disclosed for use with Laser Induced Breakdown Spectroscopy (LIBS) systems that can be applied to the real time analysis of molten materials or liquid. Since it is difficult to prepare a surface representative of the bulk when dealing with high temperature molten material, the invention, in one aspect, uses a forced gas flow through a tube insertable inside the molten material to generate a bubble. The inner surface of the bubble is a representative of the composition of the material. LIBS performed on such a surface produces an accurate real time analysis of material, even when other processing of material, e.g., copper smelting, etc., is being conducted.

Abstract: Amount of coating cure or contamination is determined. An infrared beam is transmitted into a crystal. The beam reflects off an internal face at an angle higher than critical reflection angle to generate total reflection at the crystal face. The beam exits the crystal, is filtered at two wavelengths, and is detected to give values Io1 and Io2 of infrared energy reflected without coating. A coated sample contacts an outside face of the crystal. An evanescent wave penetrates the sample where the beam reflects from internal crystal face. The beam is partially absorbed by sample, exits the crystal, is filtered at two wavelengths, and is detected to give values Ic1 and Ic2 of infrared energy reflected with coating. Absorbance values A1 and A2 at two wavelengths are A1=?log10(Ic1/Io1) and A2=?log10(Ic2/Io2). Amount of cure or contamination is proportional to ratio or difference between A1 and A2.

Abstract: Amount of opaque coating on a substrate is determined. An infrared beam is transmitted into the opaque coating on the substrate. Infrared beams scattered by the opaque coating are collected and detected at a first wavelength and a second wavelength. Infrared energy Ic1 and Ic2 of the collected infrared beams at the first and second wavelengths, respectively, are compared with predetermined values of infrared energy Io1 and Io2 of collected infrared beams at the first and second wavelengths, respectively, that are scattered by a reference substrate without the opaque coating to determine absorbance values A1 and A2 for the opaque coating at the first and second wavelengths, respectively. Absorbance values A1 and A2 at the first and second wavelengths are given by equations A1=?log10(Ic1/Io1) and A2=?log10(Ic2/Io2). A difference A1?A2 is correlated to an opaque coating amount.

Abstract: A device for measuring particulate matter includes a light source that emits light, a receiver positioned to receive light emitted from the light source, and a detection unit in communication with the receiver. The detection unit detects an amount of particulate matter based upon the light received by the receiver.

Abstract: A method for optical detection of characteristic quantities of the wavelength-dependent behavior of an illuminated specimen, such as the emission behavior and/or absorption behavior, preferably the fluorescence and/or enzyme fluorescence comprises determining at least one spectral centroid and/or a maximum of the emission radiation and/or of the absorbed radiation. An arrangement for performing the method is disclosed.