Abstract: An array of detectors of electromagnetic radiation is positioned behind a pair of “grade” or “variable” filters and are inclined with respect to each other so that the detectors view a range of center wavelengths of varying bandwidths.

Abstract: An apparatus and method capable of providing IR spectral information using IR absorption phenomena requires no moving parts or Fourier Transform during operation. IR spectral information and chemical analysis of a sample in a sample containing functional groups is determined by using an IR source, a sampling accessory for positioning the sample volume, an optically dispersive element, a focal plane array (FPA) arranged to detect the dispersed light beam, and a processor and display to control the FPA, and display an IR spectrograph. Fiber-optic coupling allows remote sensing, and portability, reliability, and ruggedness is enhanced due to the no-moving part construction. Use of the apparatus and method has broad industrial and environmental application, including measurement of thickness and chemical composition of various films, coatings, and liquids, and may also be used in real-time sensing of hazardous materials, including chemical and biological warfare agents.

Abstract: A device for detecting properties of a web of material has a crossbar extending across the web of material. An infrared spectrometer having a holographic grating is provided an has an input side and an output side. Infrared detectors are arranged at the output side of the infrared spectrometer and are formed by a detector matrix having n lines and m rows of infrared sensitive individual sensors. A plurality of optical waveguides are provided, each waveguide having an entrance area and an exit area. The entrance area is fastened to said crossbar, located in vicinity of the surface of the web of material and is oriented towards said surface. The exit areas of the optical waveguides are connected to the input side of the infrared spectrometer.

Abstract: A hemispherical detector comprising a plurality of photodetectors arranged in a substantially contiguous array, the array being substantially in the shape of a half-sphere, the half-sphere defining a closed end and an open end, the open end defining a substantially circular face. Also provided is a method for constructing a hemispherical detector comprising the steps of making a press mold of the desired shape of the hemispherical detector, pouring a material into the press mold to form a cast, finishing the cast to remove any defects, coating the cast with a coating material, and attaching a plurality of photodetectors to the cast.

Abstract: A three-color QWIP focal plane array is based on a GaAs/AlGaAs material system. Three-color QWIPs enable target recognition and discriminating systems to precisely obtain the temperature of two objects in the presence of a third unknown parameter. The QWIPs are designed to reduce the normal reflection over a significant wavelength range. One aspect of the present invention involves two photon absorptions per transition in a double quantum well structure which is different from typical QWIP structures. This design is expected to significantly reduce the dark current as a result of higher thermionic barriers and therefore allow the devices to operate at elevated temperatures. The device is expected to be fabricate using a GaAs/AlxGa1−xAs material system on a semi-insulating GaAs substrate by Molecular Beam Epitacy (MBE).

Abstract: A multi-quantum well infrared photo-detector, in which a plurality of multi-quantum well layers having respective sensitivities for different wavelength ranges of infrared are layered via a common contact layer. The infrared photo-detector includes a switch where one end is connected to the above common contact layer, and a current integration unit which is connected to the other end of the above switch. First and second voltages are applied to first and second contact layers at the opposite side of first and second multi-quantum well layer respectively. The above switch is conducted for a predetermined time so that either voltage between the above common contact layer and the first contact layer or voltage between the above common contact layer and the second contact layer becomes higher than the other, and the above current integration unit is charged or discharged by the current which flows in the above multi-quantum well layers.

Abstract: An infrared array sensor having an array of infrared sensors of different plural types for detecting infrared rays of different plural wavelength bands. Each sensor includes a diaphragm separated from a substrate by a thermally insulating cavity. The heighths of one of the diaphragm and the cavity are different in each of the plural types of sensors.

Abstract: A quantum well infrared focal plane array achieves hyper-spectral measurements of incident infrared radiation using a voltage dividing network that applies different and adjustable biasing voltages to each line of the line by column array. The peak wavelengths of each quantum well layer of each detector structure in the array is set to a specified nominal value by appropriate fabrication of the depths of the quantum wells of the layers. The nominal peak wavelength value of each quantum well layer can further be varied by modulating the bias voltage applied to the gate of the direct injection transistor associated with each detector structure of the array. A read out integrated circuit (ROIC) containing the direct injection transistor processes the photo-current from each quantum well layer of each detector structure.

Abstract: Tomographic approaches to hyperspectral imaging, such as CTHIS13 (Chromotomographic Hyperspectral Imaging Sensor), can eliminate the need for the slit, filter, or resonant cavity and substantially increase the optical throughput of the system. These systems capture most of the photon energy from the entire spectral band over the entire measurement interval. Uncooled LWIR imaging technology uses thermal based detecting elements that are less sensitive than the competing photon based cooled detecting elements, and require high optical throughput. An uncooled LWIR hyperspectral imager is described that combines a new high optical efficiency spectral imaging technique combined with a high performance uncooled thermal imager. The merging of these technologies in the current invention will significantly reduce the size, weight, and power requirements of LWIR hyperspectral systems.

Abstract: An infrared spectrometer for the determination of isotopic ratios of gaseous compounds includes a broad-band infrared light source, a spectral selector, a sample compartment, an infrared detector, and a processor. The spectral selector selectively transmits a wavelength window of infrared light covering a range of wavelengths in which the wavelength window can be selected alternatively to overlap with a wavelength range primarily absorbed by a compound with a first isotope or by the compound with a second isotope. The sample compartment holds a gas sample and includes a gas inlet and a gas outlet. The infrared spectrometer can be used to detect isotopic ratios of carbon dioxide, where enhancement of 13CO2 can indicate metabolic activity of an infection, for example by H. pylori, or of specific enzymes. Preferred embodiments use a particular multipass optical cell that includes a field mirror and a multi-segment objective mirror.

Abstract: A spectrometer includes an infrared source, a spectrally selective element, and a cell array. The cell array includes walls that define a number of cavities. The spectrometer also includes an infrared spatial detector responsive to infrared radiation travelling from the infrared source through contents of at least two of the cavities as well as through the spectrally selective element.

Abstract: A method and system for diagnosing pathology, such as carcinoma, in a biological sample identifies presence of pathology based on the existence of an infrared markers in the extracellular material, rather than cells, in the biological sample. In the case of breast cancer diagnosis, an effective marker is a baseline slope of a 1280 cm−1 band in the infrared spectra of connective tissue, with normal biopsy samples exhibiting a positive slope and cancerous samples showing a relatively flat baseline. Infrared spectroscopy, both microscopic and macroscopic, may be used to identify a sample region containing extracellular material and to collect infrared absorbance data, from which the existence of the pathology marker is determined.

Abstract: A multi-wavelength semiconductor image sensor comprises a p-type Hg0.7Cd0.3Te photo-absorbing layer formed on a single crystal CdZnTe substrate, a CdTe isolation layer deposited on the photo-absorbing layer, a p-type Hg0.7Cd0.23Te photo-absorbing layer deposited on the CdTe isolation layer, n+ regions which are formed in these photo-absorbing layers and form a pn-junction with each of these photo-absorbing layers, an indium electrode connected to each of these n+ regions and a ground electrode connected to the photo-absorbing layer, the semiconductor isolation layer being electrically isolated from the photo-absorbing layer.

Abstract: A method and apparatus for detecting the composition of a moving web product on a real-time basis during the manufacturing process. Spectrometric monitoring equipment operates to derive information regarding physical and/or chemical properties of the web at multiple locations in the web's cross direction. Data from a plurality of spectral regions can be combined to produce a vector containing accurate information regarding the web's composition. This information is derived using multivariate mathematical techniques to yield a spatial data matrix for each component of interest. Composition information contained in the spatial data matrix can be reprojected as a “virtual composition map,” or compared against ideal profiles stored in a computer memory.

Abstract: An infrared photosensitive area is constituted by an infrared ray absorbing part that is heated by infrared rays, a thermal detector that detects the temperature change of the infrared ray absorbing part, and electrodes that are electrically connected to the thermal detector. The infrared photosensitive area is held up above one surface of a substrate by supports. The electrodes of the infrared photosensitive area are electrically connected to contact pads on the substrate by wiring material that constitutes the support. A shield projects from portions of the infrared ray absorbing part other than portions that correspond to the electrodes. The contact pads of the substrate and the surfaces of the electrodes and the supports that are directed away from the substrate are covered by the shield with an interposed space. This configuration enables an increase in the fill factor of the picture elements of the thermal infrared detector and enables greater absorption of infrared light.

Abstract: A method and apparatus for an event detector using an array of passive infrared detector elements, which uses interchangeable spectral filters and lenses to permit detection of a range of event types, which normally each require individual detectors with specific spectral/optical designs.

Abstract: An infrared detector array includes a plurality of detector pixel structures, each having a plurality of coplanar sections responsive to different bands of infrared radiations. Each section of a pixel structure comprises a plurality of elongate quantum well infrared radiation absorbing photoconductor (QWIP) elements. The group of QWIP elements are spaced such that they comprise a diffraction grating for the received infrared radiation. Top and bottom longitudinal contacts are provided on opposite surfaces of the QWIP elongate elements to provide current flow transverse to the axis of the element to provide the required bias voltage. An infrared radiation reflector is provided to form an optical cavity for receiving infrared radiation. A plurality of detector pixel structures are combined to form a focal plane array. Each pixel structure section produces a signal that is transmitted through a conductive bump to a terminal of a read out integrated circuit.

Abstract: An infrared spectrometer is adapted to capture spectral data at high frequency and includes an aperture defining slit and tuning fork chopper for periodically admitting infrared radiation. A lens and a plurality of mirrors direct the infrared radiation through pair of calcium fluoride prisms that split the infrared radiation into spectral components. The spectral components are directed by an additional mirror and lens to an array of lead selenide pixels that generate a set of data indicative of the spectral component intensities. Data collection circuitry coupled to the pixel array and coupled to the tuning fork chopper collects the set of data at a selectable rate at least once during each opening of the aperture. A serial output on the data collection circuitry provides a list of data values representative of the spectral intensity at each pixel which can be then stored in a mass storage device as well as immediately analyzed based on selected criteria.

Abstract: A sensor assembly for imaging passive infrared (IR) scenes and active laser radar (LADAR) scenes and for generating multi-dimension image data sets, and a method for same. A two-dimensional semiconductor imager sensitive to both passive IR radiation and active LADAR radiation when used in conjunction with subsequent signal processing creates a two-dimension passive image data set and a three-dimension active image data set with common x and y coordinates. The passive image data set is collected substantially proximate in time with the active image data set. The two image data sets are combined to form a multi-dimension image data set with the surface of three-dimensional objects indicating heat emission. The sensor assembly applies to burst illumination LADARs operating at a variety of wavelengths and passive IR detection in the middle wavelength IR (MWIR) or long wavelength IR (LWIR).

Abstract: An apparatus for determining the concentration of a first component in a mixture of at least two components, which have different absorption properties in the IR range, comprises image recording means which are adapted to image the mixture by means of IR radiation to produce at least one image. The apparatus further comprises image processing means which, with the aid of intensity values for pixels in the image which represent the mixture, determine the concentration of the first component in the mixture.

Abstract: An apparatus for analyzing a spectrum includes an elongated source of light, a device for producing a spectrum of the light, a sample stage, and an array of photosensitive elements for detecting the spectrum and providing an output representative of an intensity of the spectrum as a function of wavelength. The sample stage is interposed between the elongated source and the spectrum-producing device. The light propagates along a length of the sample stage from the elongated source to the spectrum-producing device. The elongated source has a length greater than or equal to a length of the array.

Abstract: A spectrometer system comprises (i) a slab waveguide characterized as an index of refraction higher than a surrounding medium, and having front surface and a rear surface opposite thereto, the front surface including a input portion for accepting optical radiation, a diffractor portion and an exit portion, (ii) a diffraction grating disposed on said diffractor portion of said front surface, (iii) a detector array aligned adjacent to the exit portion, and (iv) a mirror coated on the rear surface of the waveguide. Radiation transmitted within the waveguide from the input portion is reflected and collimated by the mirror to the granting. Light diffracted from the grating is dispersed to the mirror and reflected toward and through the exit portion and onto the array.

Abstract: A spectrum of electromagnetic radiation is detected by spatially dispersing radiation of varying wavelengths onto micromechanical sensors. As the micromechanical sensors absorb radiation, the sensors bend and/or undergo a shift in the resonance characteristics. The device can be used as a spectrometer or a temperature sensing device. A temperature sensor using micromechanical sensors can accurately and quickly measure the temperature of a remote object by sensing a spectrum of infrared radiation emitted by the object. The temperature sensor can measure temperature without knowing the emissivity of the object or the distance of the object from the detector.

Abstract: Quantum-well sensors having an array of spatially separated quantum-well columns formed on a substrate. A grating can be formed increase the coupling efficiency.

Abstract: A system and method for radiation detection with an increased frame rate. A semi-parallel processing configuration is used to process a row or column of pixels in a focal-plane array in parallel to achieve a processing rate up to and greater than 1 million frames per second.

Abstract: A method and apparatus for multicolor detection employing the natural chromatic aberration of a diffractive microlens to detect two or more colors or light. In the preferred embodiment the diffractive microlens detects two colors in the VLWIR spectral region and is focused on a two-part detector having a central region to detect the shorter bandwidth and a concentrically disposed region to detect the long band, VLWIR radiation. These detectors are arranged in a multicolor focal plane array to allow imaging.

Abstract: Techniques for acquiring and analyzing M-FISH images in a manner that allows for proper image registration; and techniques for combining a plurality of registered images to provide labeled images. Epi-illumination embodiments use multiple filter cubes for different subsets of the entire set of desired dyes. The registration problem is addressed by configuring the different multiband cubes so that pairs of cubes have a common dye for which they are configured. Accordingly, a first set of images generated with a first cube includes an image that corresponds to (contains the same features as) one of the images in a second set of images generated with a second cube. This allows the first set of images to be precisely and accurately aligned with the second set of images. A method for generating a labeled image typically includes a normalization of the pixel intensities within each image, followed by a transformation to ratio images.

Abstract: A thermopile radiation detector (10) has an optical filter layer (16) that supports a thermopile detector (22) and, in addition, filters undesired wavelengths. The filtering is accomplished by selectively absorbing electromagnetic radiation at predetermined wavelengths. The use of the thermopile radiation detector simplifies the overall construction of a system that incorporates the detector by eliminating one focal point in the optical system. By altering the filter material, the number of layers of filter material, etc., a plurality of detectors can be constructed, each responsive to a different wavelength. In forming the detector, the filter can be deposited on a thin backing material such as aluminum. Examples of suitable filter materials include alternating layers of zinc selenide/magnesium fluoride or germanium/magnesium fluoride. After the filter is deposited, the backing is etched away and suitable thermocouples, such as bismuth/antimony, are deposited on one side of the filter.

Abstract: A infrared pixel sensor comprising a pixel circuit and a composite infrared pass filter comprising a plurality of filters, wherein each filter belonging to the plurality of filters are substantially transparent to infrared radiation and have a visible pass spectrum so that the composite infrared pass filter is substantially opaque to visible light. Signals from infrared pixel sensors are subtracted from color pixel sensors to correct for infrared radiation in the image signal without the need for an infrared blocking filter.

Abstract: A photoelectric conversion device comprises a semiconductor substrate, a same-dopant-type semiconductor layer, a photodiode having a charge-accumulation region, a JFET (which has a gate region, a source region, a channel region, and a drain region, the drain region electrically connected to the substrate 100), a transfer gate for transferring a charge from the photodiode to the gate region, and a reset drain having a charge-drain region for draining excess charges generated by the photodiode, the reset drain also controlling the electric potential of the gate region. Two overflow-control regions are included, one at the boundary between the charge-accumulation region and the charge-drain region within the device, one at the boundary between the charge-accumulation region and the charge-drain region of an adjacent device.

Abstract: Quantum-well sensing arrays for detecting radiation with two or more wavelengths. Each pixel includes at least two different quantum-well sensing stacks that are biased at a common voltage.