Abstract: An aqueous composition comprising a polysaccharide or polysaccharide derivative (e.g. a hydroxyalkylcellulose), an electrolyte (e.g. a water-soluble inorganic salt), and an aqueous medium and having a clouding point is hermetically interposed between a pair of electrodes to produced a light shielding device. The clouding point of the aqueous composition can be controlled by adjusting the concentration of the polysaccharide or polysaccharide derivative and/or the species and concentration of the electrolyte. An electric field is applied to the electrodes to control the clouding point of the aqueous composition for selective switching from transparency to opacity or vice versa, thus causing the light shielding device to discharge its light-shielding or dimming function. The light-shielding or dimming effect is obtained regardless of changes in ambient temperature.

Abstract: A multi-layer structure for controlling the transmission laser radiation including an outer layer which is slightly absorbent to incident laser radiation and an intermediate layer which is substantially absorbent to incident laser radiation to achieve significant attenuation of on-axis transmission of laser radiation in an otherwise transparent structure.

Abstract: A multi-layer structure for controlling the transmission laser radiation including an array of polydispersing scatterers in an intermediate layer. The outer layer is made of a material which partially ablates when exposed to incident laser radiation, generating an irregular surface which initially scatters the incident laser radiation. The initially scattered radiation is transmitted to the intermediate layer containing the array of monofilament fibers which further scatters the laser such that combination achieves substantial attenuation of on-axis transmission of the laser radiation in an otherwise transparent structure.

Abstract: A multi-layer structure for controlling the destructive effects of laser radiation including means within the structure for conducting the heat generated in the outer layer by the incident laser radiation away from the outer layer to achieve significant mitigation of the destructive effects of the laser radiation in a transparent structure.

Abstract: A multi-layer structure for controlling the transmission of laser radiation including outer and intermediate layers absorbent to incident laser radiation. The outer and intermediate layers ablate under the influence of the incident laser radiation to achieve substantial attenuation of on-axis transmission in an otherwise transparent structure.

Abstract: The present invention relates to a window tinting apparatus (10) which comprises an outer window (16A) and an inner window (16B) having a window cavity (16C) there between. The window tinting apparatus (10) further comprises a first primary polarized panel (12A) securely affixed to the window (16A, 16B). The first primary polarized panel (12A) comprises a plurality of first primary polarized panel longitudinal polarization lines (12AA) therein. The window tinting apparatus (10) further comprises a secondary polarized panel (14) slidably mounted within the window cavity (16C). The secondary polarized panel (14) comprises a plurality of secondary polarized panel longitudinal polarization lines (14B). The secondary polarized panel (14) further comprises a secondary polarized panel ledge (14A) attached at a distal edge. The secondary polarized panel longitudinal polarization lines (14B) and the first primary polarized panel longitudinal polarization lines (12AA) are parallel to one another.

Abstract: A radiation apparatus comprising a radiation source and a filter arranged in an optical path, said filter comprising two transparent filter discs which are arranged substantially in plane-parallel fashion relative to each other and which are held with their surrounding edges in a frame made of a material of good heat conduction, the filter discs and the frame defining a closed cavity which has provided therein a medium for selectively influencing the radiation spectrum. The frame is divided substantially in a direction transverse to the filter axis into first and second frame halves in such a manner that the one filter disc is arranged on the first frame half at the side facing the cavity and the other filter disc is arranged on the second frame half at the side facing the cavity.

Abstract: Novel sensor devices composed of a crystalline colloidal array (CCA) polymerized in a hydrogel are disclosed. The hydrogels are characterized as being capable of shrinking and swelling in response to specific stimuli applied thereto. As the hydrogels shrink or swell, the lattice structure of the CCA embedded therein changes, thereby changing the wavelength of light diffracted by the CCA. Thus by monitoring the change in diffracted wavelength, the concentration of a stimulus is determined. The gels can be modified to sense numerous different stimuli. The sensor devices are specific in that they are modified to react with only one species or family of species. These sensors have various applications in areas including, for example, environmental and chemical systems, chemomechanical systems, sensor devices and medical diagnostic tools. Various methods for making and using these devices are also disclosed.

Abstract: An optical system is provided comprising an entry window, an exit window, a radiation transmissive membrane, and first and second lenses. The entry window and the exit window define a radiation path extending from the entry window to the exit window. The radiation transmissive membrane is positioned along the radiation path between the entry window and the exit window. The membrane defines a first chamber between the entry window and the membrane and a second chamber between the membrane and the exit window. The first fluid is included within the first chamber so as to intersect the radiation path and the second fluid is included within the second chamber so as to intersect the radiation path. The first lens operative to focus radiation directed through the entry window at a focal point located within the second fluid. The second lens is operative to focus radiation passing through the exit window.

Abstract: An adjustable window tinting system for producing varying degrees of tint in a window to thereby limit the amount of light and heat pass through a window. The device includes two panes of glass, a darkening mechanism which separates and merges the two panes of glass, and an opaque fluid that enters between the two panes of glass at various thickness depending upon the amount of separation of the two panes of glass. The various degrees of tint are thus attained from the various thickness of the opaque fluid, varying from substantially opaque to transparent.

Abstract: An optical device functioning as a variable apex angle prism and suitable to be incorporated in an image stabilizing apparatus for an optical apparatus is constituted by a pair of transparent circular plates disposed oppositely spaced from each other, a connecting member attached to the circular plates so as to define a closed space in combination with the circular plates and deformable under application of an external drive force, and a transparent substance disposed within the closed space. The transparent substance comprises at least one compound selected from the group consisting of polyether-modified organopolysiloxane, polyether alcohol-modified organopolysiloxane and fluorine-containing compounds.

Abstract: A window shutter device for automatic regulation of solar illumination in response to variations in external sunlight. Gas pressure change in a sunlit cavity causes fluid displacement between two transparent window panes. A transparent fluid is displaced by another fluid which blocks part of the sunlight falling on the panes. Glare is prevented while preserving adequate interior illumination and a clear view outside the window.

Abstract: A surface of a thin film superconductor element is coated with a layer containing pre-selected dye, or multiple dyes, alone or in combination with intermediate reflective coatings (best mode), which, when maintained near T.sub.c, upon exposure to a selected frequency of light acts as a narrow bandwidth absorber to change the resistive property of the underlying superconductor following energy transfer from the dye to the superconductor. The resistance change is electronically detectable to function as a wavelength selective high speed optoelectronic switch or sensor element.

Abstract: A broadband thermal optical limiter disposed between a laser oscillator and laser amplifier system for protecting optical components in the laser oscillator from damage due to amplified optical feedback from the laser amplifier system at all near ultraviolet, visible and near infrared wavelengths is disclosed.

Abstract: In order to protect a delicate photodetector from high-intensity radiation, such as from a laser, a device for limiting optical power to the detector is interposed between the radiation and the detector. This device has an optical interface that totally reflects high-intensity radiation, but which freely transmits normal (low intensity) radiation to the detector. The interface is between two optical materials, one with a linear index of refraction with respect to radiation intensity, and the other with a non-linear index. At low intensity radiation levels, the two materials have the same indices of refraction, and such radiation is freely transmitted through the interface, but with high-intensity radiation, a mismatch of indices of refraction allows total reflection at the interface.

Abstract: Novel squarylium dyestuffs are formed by condensing one molecular equivalent of squaric acid with two molecular equivalents of a heterocyclic intermediate of the formula ##STR1## in which X is an optionally substituted ethylene or o-phenylene group; Y is an optionally substituted methylene or imino group, oxygen, sulfur, selenium or (if X is ethylene) a direct bond; and R.sub.1 through R.sub.5 are various substituents or (except for R.sub.2 and R.sub.5) hydrogen. A preferred class of dyestuffs are those formed from intermediates in which Y is methylene or a direct bond, the former including 7-acylaminotetrahydroquinolines and the latter including 6-acylaminoindolines. Thus, two molecular equivalents of each of 1-methyl-7-acetamido-1,2,3,4-tetrahydroquinoline and 6-acetamido-1,2,3, 3-tetramethylindoline were condensed with one molecular equivalent of squaric acid to produce respective dyes each having an absorption maximum substantially coincident with the ruby-laser wavelength of 694 nm.

Abstract: A panel system with variable light transmissiveness is formed of two essentially parallel transparent panels, and a seal encircling both panels. A cavity, defined by the panels and the seal, communicates with a liquid reservoir, from which liquid can be conveyed into the cavity by a transport element for the purpose of changing the distance between the panels by changing the thickness of the liquid layer between the panels. In order to render the panel system suitable for usage in a cover of a vehicle sliding/lifting roof, the liquid reservoir and the transport element, which is driven by a pole-reversible electric motor, are supported at an inner cover plate, which has an undercut in an edge portion in which an electrical contact element for establishing a conductive connection between the electric motor and the vehicle battery is disposed.

Abstract: Methods for making a nonlinear optical device and related devices are dissed. The method includes creating an ordered dispersion of charged particles in a surrounding medium. The charged particles and the surrounding medium are chosen such that they initially have identical refractive indices. In accordance with one aspect of the invention, cadmium sulfide inclusions are added to at least one of (a) the particles or (b) the medium. The cadmium sulfide inclusions have a highly nonlinear refractive index. The inclusions are optically nonlinear and upon high intensity radiation the refractive index of the particles change. This change in the refractive index occurs on the order of nanoseconds. In accordance with another aspect of the invention, a nonfluorescent dye is incorporated into at least one of (a) the particles or (b) the medium. The dye is photoabsorptive. Upon being impinged with high intensity radiation, the dye absorbs photons and heats the surrounding particles.

Abstract: Calibration of a wavelength adjustment mechanism of a laser is achieved using a hollow cathode absorption lamp. The lamp is provided with a vaporous material having a precisely known wavelength of maximum absorption. A photo-detector detects the amount of light from the laser beam absorbed by the vaporous material as a function of wavelength. The wavelength of the laser is adjusted to achieve maximum absorption such that the actual laser beam wavelength may be compared with an expected, wavelength to determine a calibration offset. The hollow cathode lamp is operated to produce a vaporous material of known absorption characteristic but is illuminated at a level substantially below a level required for conventional opto-galvanic resonance.

Abstract: The present invention discloses a tunable, radiation filter comprising a highly ordered crystalline array of microparticles fixed in a polymerized hydrogel.

Abstract: The present invention discloses radiation filters comprising a highly ordered crystalline array of microparticles fixed in a polymerized hydrogel in which is contained simple sugars or polyhydric alcohols to provide additional low temperature stability.

Abstract: The present invention discloses radiation filters comprising a highly ordered crystalline array of microparticles fixed in a polymerized hydrogel.

Abstract: The present invention discloses satellite peak free radiation filters comprising a highly ordered crystalline array of microparticles fixed in a polymerized hydrogel.

Abstract: (S) A first optical material with a linear index of refraction is distributed as particles in a second optical material with an index of refraction dependent on the incident radiation intensity. Below some threshold intensity level the combination of materials is transparent to incident radiation directed toward a sensitive optical detector. Above this level, high-intensity incident radiation induces a change in refractive index of the second material, and the combination is limiting to incident radiation.

Abstract: Two new passive atomic filters that operate at 422.67 nm and 460.73 nm respectively are disclosed. The filter wavelengths overlap Fraunhofer lines, thereby providing outstanding sunlight rejection. The new calcium filter utilizes collisional energy transfer with Xenon to wavelength shift the violet light to 657.28 nm. An internal photon conversion efficiency of 25% was recorded. The new strontium filter utilizes collisions with noble gases to produce emission at 689.26 nm. An internal photon conversion efficiency of 45% was recorded.

Abstract: A laser protection device employing a gas plasma switch wherein applied laser radiation is focused inside a gas chamber, and a nuclear source is employed to pre-ionize the gas volume, whereupon focused laser radiation causes gas breakdown and plasma formation that attenuates the radiation. Specifically, the invention reduces the threshold of plasma switch initiation by incorporating a nuclear source within the gas chamber that constantly injects plasma forming seed particles into the vicinity of a focused laser beam. The plasma resulting from avalanche ionization of the seed particles reflects, absorbs and deflects the laser radiation. The nuclear source introduces charged particles, excimers and metastable atoms with low ionization potential into the gas chamber. Such charged particles are effective plasma initiators because they have low ionization thresholds. The present invention has been found well suited to protect against pulsed laser sources because of fast rise times and high attenuation levels.

Abstract: Optically sensitive materials such as sensors or the human eye are passively protected against overexposure to high intensity ligGOVERNMENT RIGHTSThis invention was made with Government support under Contract No. N62269-87-C-0263 awarded by the Department of the Navy. The Government has certain rights in this invention.

Abstract: The present invention discloses a tunable, radiation filter comprising a highly ordered crystalline array of microparticles fixed in a polymerized hydrogel.

Abstract: A liquid display device includes a transparent display board assembly having a flat, water-tight compartment on the inside, and a piston pump assembly controlled by a reversible motor to reciprocate two or more kinds of liquids of different colors and different specific gravities in changing the transparency of the transparent display board assembly so as to regulate the light passing through.

Abstract: A color scanner has a plurality of rows of photosensors. Spacers are formed between and around the rows, and a transparent cover sheet is sealed to the device, to form separate channels. An opening is provided in each otherwise sealed channel. The channels are filled with different colored media by evacuating the channels and letting the vacuum draw in different colored media such as liquids or gels.

Abstract: A head lamp device for automobiles has a light source and a cover member arranged in front of the light source. The light source is comprised of a transparent hard resin plate curved outwardly at its central part, and a transparent soft resin sheet intimately in contact with a rear surface of the transparent hard resin plate with a peripheral edge of the transparent soft resin sheet attached fluid tight to a peripheral edge of the transparent hard resin plate. The transparent hard resin plate has a pipe through which a colored solution is supplied into and removed from a space formed between the transparent hard resin plate and the transparent soft resin sheet.

Abstract: A kinetic art article assembly with stacked color filter comprises a base, two support plates, a cylindrical main body with a front main body and a rear main body, a fluid governor, and a drive mechanism. At least a set of plate assembly is disposed in the front main body and the rear main body. The plate assembly has a front plate, a flat plate and a rear plate. Each of the flat plate and the rear plate has a tube thereon so that liquid in the tube can flow in to the recesses of the front plate or the rear plate.

Abstract: A method is provided in which the pulse stretching effects of radiation trapping can be minimized in atomic resonance filter detectors or QLORD filter detectors of the type described in U.S. Pat. No. 4,292,526. The QLORD detector of this invention which consists of two spectral bandpass filters, one each located on either side of a transparent cell containing an alkali metal vapor (preferably cesium vapor), and responds to an incoming pulse in the visible part of the spectrum of light (actually 420 to 480 nm), emitting a pulse of infrared light. If the transparent cell contains alkali metal vapor only, the infrared light pulse will be stretched, because of resonant trapping within the alkali metal vapor. However, in accordance with the present invention, an inert buffer gas (namely helium) is added to the alkali metal vapor. This buffer gas allows the rapid leakage of infrared light photons from the wings of the energy spectrum, and hence a more rapid response to the incoming pulse.

Abstract: A solid colloidal optical wavelength filter includes a suspension of spheal particles dispersed in a coagulable medium such as a setting plastic. The filter is formed by suspending spherical particles in a coagulable medium; agitating the particles and coagulable medium to produce an emulsion of particles suspended in the coagulable medium; and allowing the coagulable medium and suspended emulsion of particles to cool.

Abstract: A spectral bandpass filter with a sharp angle independent absorption edge for reducing optical noise is used in conjunction with a known atomic resonance filter-detector or QLORD detector such as described in U.S. Pat. No. 4,292,526. The QLORD detector comprises two spectral bandpass filters enclosing or sandwiching a chamber containing atomic vapor. In accordance with the present invention, between the high-pass filter and the atomic vapor is placed a strip of volume absorbing filter material. The high pass filter has already admitted light which can be absorbed by the atomic vapor thereby excluding that incoming light which is in the spectral range of the light readmitted by radiative decay. The volume absorbing material then makes the further attenuative selection between the various sets of hyperfine lines.

Abstract: A narrow passband, reflective optical filter at a wavelength L, has a container filled with a pressurized gas, the pressurized gas having a ground state transition corresponding to the wavelength L and transparent to all other wavelengths. The container has at least one optically transparent major planar surface serving as the face thereof, whereby incoming broadband light is absorbed by the gas, except at its resonance wavelength L, which is specularly reflected. The optically transparent face of the container optionally has a broadband anti-reflective coating to improve its out-of-band rejection of unwanted wavelengths of the light signal.

Abstract: A laser beam stop is contructed having a uniquely designed cell filled with solution or suspension of an absorbing species chosen to absorb the wavelength of light emitted by the laser. The position and strength of the laser beam are indicated by the strength and depth of penetration of the fluorescence excited by the laser.

Abstract: By controlling the temperature of a glass reservoir tube attached to a closed vapor cell, the vapor pressure inside the cell can be accurately controlled. The apparatus for controlling the reservoir temperature includes an electric heater, a temperature sensor, heat straps to distribute and remove heat from the reservoir, and a clamp to hold the apparatus in close thermal contact with the exterior of the reservoir. An external control circuit energizes the reservoir heater as required. In the preferred embodiment the vapor cell functions as an optical filter when filled with a heated metallic vapor such as cesium. The reservoir tube functions as the cold spot of the cell and contains a small pool of the metal in liquid form.This invention was made with Government support under N66001-86-R-0050 awarded by the Department of the Navy. The Government has certain rights in this invention.

Abstract: A non-imaging optical telescope having a variable field-of-view utilizes an atomic resonance filter within its non-reflective tube. The atomic resonance filter received incoming light through the aperture of the telescope and re-emits the light to an optical sensor. The field-of-view is a function of the distance of the atomic resonance filter from the aperture. A positioning mechanism is provided to move the atomic resonance filter within the tube, thereby varying the field-of-view.