Abstract: A scintillation based microscope. One surface of a single crystal salt crystal scintillator is supported on an optically transparent support plate. The opposite surface, an illumination surface, of the crystal is coated with an optically reflecting material which is transparent to high energy photons (such as x-ray and/or high energy ultraviolet photons) in order to provide a scintillation sandwich having an optical mirror at the illumination surface of the crystal. These high energy photons are directed through a target to create a shadow image of the target on the illumination surface of the scintillator salt crystal. A portion or all of the shadow image is viewed with an optical device such as an eye piece to provide a very high resolution image of the target or portions of the target. In a preferred embodiment an adjustable pin hole unit is described to produce a very small x-ray spot source for producing high resolution geometric magnification of the shadow image of the target.

Abstract: A thin diamond electron beam amplifier. The illumination side of a thin diamond is illuminated by a seed electron beam creating electron-hole pairs in the diamond. A voltage potential provides an electric field between the illumination side of the diamond and an acceleration grid opposite the emission side of the diamond. Electrons released in the diamond are accelerated through the emission side of the diamond toward the acceleration grid creating an amplified electron beam. Preferred embodiments of the present invention are useful to provide flat panel displays and replacements for thermionic cathodes, cathode ray tubes, fast photodetectors and image intensifiers.

Abstract: A semiconductor imaging device comprising MOS or CMOS pixel circuits having pixel pads separated by insulating material and having a conductive migration blocking layer applied over the pixel pads. The conductive migration blocking layer comprises an electrically conductive material that is inert with respect to selected photoelectric conversion layer materials, and may be formed as individual contacts, or formed as a deposited layer and etched to form distinct pixels covering the underlying pixel pad material. Thereafter, a photoelectric conversion layer is applied over the migration blocking layer material. The basic device is completed by applying a field electrode layer over the photoelectric conversion layer.

Abstract: An imaging device for producing images from electron-hole producing radiation. Electron-hole pairs are produced in a radiation absorbing layer comprised of a photoconductive material. This layer covers an array of metal oxide semiconductor pixel circuits which are incorporated into and on a crystalline semiconductor substrate. Each pixel circuit has a charge collecting pixel electrode, a capacitor connected to the electrode to store the charges and a charge measuring transistor circuit. A voltage source provides an electric field across the radiation absorbing layer between the pixel electrodes and a radiation transparent surface electrode covering the radiation absorbing layer. A data acquisition system acquires and stores data derived from charge measurements and in a preferred embodiment a computer computes images from the data. The image may be displayed on a monitor or printed out on a printer. Preferred embodiments provide images from x-ray, ultraviolet and visible light.

Abstract: An x-ray imaging device. One surface of a flat single crystal CsI crystal is supported on an optically transparent support plate. The opposite surface, i.e. an x-ray illumination surface of the crystal is coated with an x-ray transparent optical reflector to provide an x-ray scintillation sandwich having an optical mirror at the x-ray illumination surface of the CsI crystal. An optical camera is preferably focused on the illumination surface of the CsI crystal. In a preferred embodiment an index of refraction matched optical adhesive is used at the x-ray illumination surface to attach the reflector and to reduce Fresnel reflections.

Abstract: The invention provides a digital x-ray mammography device capable of imaging a full breast. A movable aperture coupled with a movable x-ray image detector permits x-ray image data to be obtained with respect to partially overlapping x-ray beam paths from an x-ray source passing through a human breast. A digital computer programmed with a stitching algorithm produces a composite image of the breast from the image data obtained with respect to each path. In a preferred embodiment, a Schmidt camera images visible light produced at an x-ray to visible light conversion surface onto a digital detector array to produce an overlapping image pane with respect to each overlapping beam path.

Abstract: This invention provides an imaging system for producing images from electromagnetic radiation such as x-rays. The system includes a detector comprised of a radiation-absorbing layer sandwiched between an array of CMOS integrated circuits (which we call pixel circuits) and a surface electrode layer transparent to the radiation. Each of the pixel circuits in the array has a charge collecting electrode. An external voltage applied between the surface electrode layer and the charge collecting electrodes produces an electric field across the thickness of the absorbing layer. Radiation passing through the transparent surface electrode layer is absorbed in the absorbing layer creating electron/hole pairs in the absorbing layer. A portion of the liberated holes (or electrons) migrates under the influence of the electric field toward the charge collecting electrodes, which collect the holes and store them as charges on small capacitors located within each circuit.

Abstract: A laser Doppler velocimeter. A laser produces a single frequency beam which is split into a probe beam and a reference beam. The probe beam is directed at a moving target and a portion of the light reflected from the target is collected, formed into a beam. Both the reference beam and the reflected beam passed through an atomic line filter in which a vapor cell is subjected to a constant magnetic field and a second magnetic field which is being oscillated. Light of the reference beam and the reflected beam passing through the filter is detected and analyzed at the frequency of oscillation of the second magnetic field and at twice that frequency. The speed of the target can be determined from measurements with respect to each beam of the amplitudes at these two frequencies.

Abstract: A broadband spectrum analyzer for radio frequency and microwave signals. The signal to be analyzed modulates an optical laser beam through an electro-optic modulator. The resultant modulated beam thus comprises light at a frequency (carrier frequency) corresponding to the wavelength of the laser beam and frequencies close to the carrier frequency corresponding to the frequencies representing the modulating signal. The modulated beam is expanded to produce a beam with light traveling in a large number of directions within a narrow angle. The expanded beam illuminates the aperture of an etalon. The etalon functions as an optical filter passing only portions of the beam which enter the etalon at an angle such that the distance traveled by the light within the etalon equals an integral number of wavelengths. Thus, different frequencies pass through the etalon at different angles. The output from the etalon is collected by a video camera for display and interpretation.

Abstract: This invention provides an acoustic imaging device which utilizes scattered acoustic wave information to produce an image. The system consists of an array of acoustic transducers which at least partially encircle a medium to be imaged. The medium is sequentially insonified by each transducer with an acoustic signal comprised of at least one discrete frequency. The acoustic signal scatters from the medium and is detected by the remaining transducers. A data set representing the phase and amplitude of each discrete frequency at each transducer is acquired and used by a computer to calculate an image of the medium. Images acquired and calculated at each identifiable discrete frequency are combined in various ways in order to improve the quality of the final image of the medium.

Abstract: This invention provides an acoustic imaging device in which a large number of transducers are spaced less than a half acoustic wavelength apart on a circle surrounding an object to be imaged. A signal generator generates discrete acoustic frequencies in the range of 100 kHz to 1.5 MHz. Multiplexer systems are provided to permit each transducer, one at a time, to broadcast a signal while the broadcast signal is detected by the other transducers. Electronic equipment records the detected signal and from the recorded information phase and amplitude data is calculated with respect to each transducer location. A computer programmed with an algorithm computes images of slices through the object using the phase and amplitude data. We utilize single frequency, steady-state acoustic signals which enables the accurate determination of the phase and amplitude of the acoustic signals at each receiver transducer.

Abstract: A device and method for producing an image of a fluid moving through a medium. An acoustic wave insonifies the medium to produce Doppler shifted scattering from randomly located scatterers in the moving fluid. At least eight channels of acoustic detectors detect signals reflected from the medium and the amplitudes of the scattered signal is determined at each channel for at least one Doppler shifted frequency. Time averaged channel-to-channel amplitude correlations are produced using the Doppler shifted amplitude data from which the image of the moving fluid is calculated.

Abstract: An acoustic imaging device is disclosed which utilizes mathematical inversion of scattered acoustic wave information to produce an image. A preferred embodiment of the device consists of a ring of acoustic transducers which encircle a medium to be imaged. The medium is sequentially insonified by each transducer with subsequent reception of the scattered waves by the remaining transducers. Explicit mathematical inversion of the scattered wave data using a remap algorithm results in a two-dimensional map of the scattering potential of the medium. Sound speed and density maps can be obtained from a map of the scattering potential. This device is utilizable for imaging of human tissue in vivo and in vitro, and for nondestructive evaluation of materials.

Abstract: A camera system in which microwave radiation from objects in a field-of-view is collected by an antenna having a beam direction which is a function of the beam frequency. The collected radiation is analyzed to produce an image of the objects in the field-of-view. In a simple embodiment of the invention a one dimensional image is produced. This one dimensional image can be converted to a two dimensional image by rotating the camera system or mounting the camera on a moving platform. In a preferred embodiment of the present invention the microwave radiation collected by the antenna is converted into electronic acoustic signals which sets up a diffraction pattern in a Bragg cell to diffract a laser beam which is focused on a television camera to produce one dimensional image of the field-of-view. The antenna can be scanned to produce a two dimensional image. In another preferred embodiment an array of antennas and a multi-channel Bragg cell is used to produce a two dimensional real time image.

Abstract: A compensating beamformer which requires orders of magnitude fewer calculations that prior art methods. A compensating beamformer is provided which comprises a plurality of sensing elements and a plurality of analog-to-digital converters, for converting incoming analog signals to digital form. Digital signals from at least four such elements are used to compute phase angle information which is combined to form a matrix of input data in the frequency domain. An unweighted steering vector is determined to sample data from the target direction. A corrector matrix is calculated based on input data from sensing elements. That corrector matrix along with its inverse, which is determined recursively, is used in combination with the unweighted steering vector to determine an optimal steering vector. The input data in the frequency domain are then multiplied by the optimal steering vector to obtain signals in the directions of interest.

Abstract: A telescope with a spherical primary mirror and a movable secondary optical element which is positioned at various locations near the focal plane of the primary mirror and directs a portion of the focused radiation to a coude optics device at the center of curvature of the primary mirror. The coude optics device reflects the focused radiation to a detector. In a preferred embodiment of this invention a field of several degrees can be scanned very rapidly while viewing much smaller object fields.

Abstract: A 3-D visual display apparatus. A sealed chamber having one or more walls transparent to visible light contains a gas having a first excited state and a second excited state which second excited state relaxes with the emission of visible light. A first laser source excites a small first volume of the gas to the first excited state and a second laser source excites a second volume, which is a small portion of the small first volume, to the second excited state which relaxes to emit visible light in all directions from the small second volume. This small light emitting volume appears as a small spot of light. Rapid movement of the two lasers permits the creation of other light emitting spots quickly enough to produce what appears to the human eye as a 3-D display. By proper choice of gases and lasers, visible light in all colors can be emitted from the spots to produce a 3-D color display.

Abstract: A wavefront, such as from a laser, is sampled, preferably at a beam splitter to break off only a fraction of the total light energy. The sampled beam is adjusted and sized--either by expansion or contraction at a conventional telescope--and thereafter sent through paired crossed Ronchi gratings and onto a CCD camera located at the first wave distance of constructive interference from the crossed Ronchi gratings. The crossed Ronchi gratings--in the order of 200 lines per inch and preferably with 200 equally spaced gaps per inch--project an array of square spots onto the focus of the CCD camera. The image of the array of square spots at the CCD camera is frozen via a frame grabber and digitized in a conventional format. The digitized image is played through a disclosed computer program to locate the spots. Thereafter, the located spots are compared to a standard spots.