Abstract: A high voltage switch tube with a central cathode cylindrically symmetric to and surrounded by a tubular anode, with a grid interposed between the cathode and anode. A high negative voltage is applied to the cathode, but the flow of electrons to the anode is blocked by the grid which is held near cathode potential. After a space charge is created at the grid by electrons from the cathode, the grid is pulsed to ground potential, releasing electrons from the cathode to yield a very high current pulse. The cathode is preferably a graphite foam sleeve mounted on a support structure.

Abstract: An optical image processor utilizes a source of partially coherent light and a spatial filter with a highly selectable modulation transfer function for processing an image, which may be present in real time. The spatial filter contains electro-optic material with electrodes arranged on such material to form a plurality of annular bands of different radii that are concentrically-situated and invididually-addressable. The annular bands are changeable in transmissivity in a continuous spectrum from transparent to opaque in response to an electrical signal on the respective electrodes of the bands. A first optical transmission path receives the image to be processed and optically transmits the image to the spatial filter for processing. A second optical transmission path receives the image processed by the spatial filter and optically transmits the image to an output port.

Abstract: A tunable millimeter wave source in which accelerated electrons are directed into a bending magnet and emit broadband radiation in the millimeter wavelength portion of the spectrum. The electrons are produced by an electron gun using a portion of the microwave energy output from a RF source. The remainder of the microwave energy from the RF source is used to drive an RF linear accelerator which accelerates the electrons and directs them into the bending magnet. An interferometer may be used to select radiation of a particular frequency from the broadband output of the source. In a second embodiment, the source is provided with a plurality of output apertures, and a plurality of respective interferometers are used to select radiation of a number of desired discrete frequencies.

Abstract: A multi-layer device for modulating and reflecting light. The device is formed of an electro-optic layer with a variable index of refraction sandwiched between two other layers having a pre-determined index of refraction. An electric field applied across the electro-optic layer controls the index of refraction of the layer and thus the reflectance and transmittance of light through the multi-layer stack. The device can therefore be used as a mirror, window, beam-splitter, shutter, light modulator, or other optical logic element.

Abstract: An X-ray source with a cathode formed as a cylindrical electrode having a hollow central anode tube on its axis, with a grid surrounding the anode and interposed between the anode and cathode. The central anode tube is hollow and filled with a working medium. A high negative voltage is applied to the cathode, but the flow of electrons to the anode is blocked by the grid which is held near cathode potential. After a space charge is created at the grid by electrons from the cathode, a very short pulse to ground is applied to one end of the grid, yielding a relativistic wave of potential which propagates along the axial length of the grid. This wave of potential releases the electrons from the cathode, which flow directly to the anode. The impingement of the electrons on the tubular anode produces X-rays from the interior surface of the anode tube.

Abstract: A pre-excited excimer laser is formed in a thin flat package. Input X-ray photons which are modulated by passing through a body to be analyzed raise the pre-excited excimer gas molecules to a lasing energy level and the coherent radiation produced is measured and produces an amplified image of the input X-ray photon modulation.

Abstract: An X-ray tube has a wide area cold cathode with a graphite felt surface which faces and is spaced from a wide area anode of high atomic number material. A grid is interposed between the two and the anode, grid and cathode are enclosed in an envelope which is filled with gas at a low pressure. The graphite surface of the cathode is connected to a relatively high negative potential so that electrons are emitted from the entire surface area and impinge upon the anode, after triggering by the grid. The distribution of the energy of photons emitted from the anode is relatively constant during the ignition period of the tube. An extremely wide area X-ray source is then defined having constant bremstrahlung content which enables good gray scale measurements when employing the X-ray source. A pinhole collimator disposed externally of the tube ensures collimation of the output X-ray field.

Abstract: Objects to be examined, such as tissue or any cellular or crystalline material, e.g. semiconductor wafers, are placed in a region of confluence of two interfering coherent beams of radiation which are at the same frequency and phase and at a frequency to which the object is semi-transparent. The beams are produced by separate sources or by refraction by a Fresnel biprism or any other interferometer structure. An off-axis parabolic reflection system is also disclosed. The interference fringe phase and amplitude perturbation produced by the object is detected and examined to derive information regarding physical properties of the object or abnormalities in its structure. Such abnormalities, as fractures or latent stresses in a semi-conductor wafer or the presence of tumors in biological tissue can be determined.

Abstract: An optical processing system based on noncoherent light processing employs both geometrical and diffraction optical systems. One portion of the optical system performs a subtraction operation of the image from itself where one of the subtracted images is relatively defocused and one is delayed in time from the other. The subtracted image is edge-enhanced and then applied to a spatial filter employing an interferometer in which spatial filters are contained in the interferometer iris plates. Additional spatial filtering is performed on the interference image and the processed image is displayed in an appropriate display which can selectively view the processed image, the unprocessed image or combinations of the two. Light storage elements are employed for storing the processed images in appropriate buffers over a given length of time. The buffers are read out by a flashlamp. Suitable shutters are closed during the readout process.