Patent application number | Description | Published |
20080279231 | Optical limiter - An optical power limiter comprises an input optical transmission element, an output optical transmission element, and a power-limiting element disposed between the input and output elements for transmitting optical signals from the input element to the output element. The power-limiting element comprises an optical-limiting solid mixture containing particles of at least one material that produces reversible thermal changes in response to light above a predetermined optical power level, thereby changing the optical transmission properties of the power-limiting element. | 11-13-2008 |
20090073053 | OPTICALLY DRIVEN ANTENNA - There is provided an optically driven, transmitting and receiving antenna transformable into an electrically invisible antenna when inactive, including a light source, a semiconductor wafer illuminatable by the light source and a microwave source or sensor. The wafer has a surface for forming optically induced plasma or electron hole concentration, assuming a spatial and temporal pattern defined by a light beam impinging thereon. Upon the wafer being exposed to the light beam having a power level sufficient for creating a dense plasma or electron hole concentration in the wafer, the wafer becomes reflective to microwaves, and returns to transparency when light from the light source is turned off. | 03-19-2009 |
20090122298 | Optical Screen, Systems and Methods For Producing and Operating Same - There is provided a system for forming an optical screen, including a continuous wave or pulsed laser transmitter for transmitting a beam of radiation at a predetermined wavelength and forming a planar or curved surface to be traversed by a moving object, at least one receiver including an array of detectors for receiving reflected or scattered beam radiation from the object and directing it towards the detectors for producing a signal, and a detection logic receiving the signal and determining parameters selected from the group of spatial position, velocity and direction of propulsion of the moving object. A method for detecting a moving object is also provided. | 05-14-2009 |
20090207478 | Optical power limiting and switching combined device and a method for protecting imaging and non-imaging sensors - An optical power limiting and switching device comprises at least one plate made of transparent dielectric material, and a thin limiting solid mixture coated on one side of the plate. Upon being exposed to an optical power beam having a power level exceeding a predetermined limit power, the layer of solid mixture limits the power transmission by scattering out part of the impinging energy. When the power increases to the damage threshold, the solid mixture forms a plasma or catastrophic breakdown, damaging the solid mixture material and thereby rendering the portion of the plate surface under the impinging beam opaque to light. | 08-20-2009 |
20090304040 | DIODE-PUMPED CAVITY - A side-pumped, diode-pumped solid-state laser cavity includes a conductively cooled housing having an opening O for pump radiation from a diode array in close proximity to a laser rod. The pump light is absorbed by the rod and excites the laser ions. The cavity includes a thin, diffuse reflector encircling the rod, having a shaped opening for the collection and redirection of the pump light into the rod, and a good heat conductor as the heat sink and heat conductor. A split heat sink inhibits the flow of heat from the pump diodes into the laser rod, and pre-formed air spacings are designed to provide uniform temperature distribution around the laser rod. | 12-10-2009 |
20100061680 | RESETTABLE OPTICAL FUSE - A resettable optical energy switching device comprises a waveguide forming an optical path between an input end and an output end, and an optical energy diverting material located in said optical path for diverting optical energy propagation away from said output end when said optical energy exceeds a predetermined threshold. The optical energy diverting material does not divert optical energy propagation away from the output end when the optical energy propagation drops below the predetermined threshold, and thus propagation of optical energy to the output end is automatically resumed when the optical energy drops below the predetermined threshold. In one implementation, the optical energy diverting material comprises a light-absorbing material having an index of refraction that decreases as light is absorbed by the material. | 03-11-2010 |
20100084383 | METHOD FOR LASER INDUCED FUSION PIGTAILING OF OPTICAL FIBER TO OPTICAL WAVEGUIDE - A method for instant splicing of an optical fiber to an optical waveguide or bulk material comprises forming a nanometric conductive layer at the interface between the optical fiber and the optical waveguide or bulk material to be spliced, and applying laser radiation to the interface through the fiber optical internally or through the bulk material externally, to produce an arc discharge due to the laser light electric field. The arc discharge melts and diffuses the conductive layer to produce a permanent splice having a low optical loss. | 04-08-2010 |
20100145417 | LICE EXTERMINATION SYSTEM AND METHOD - Apparatus is provided for treating an infested area ( | 06-10-2010 |
20100166368 | GRATING LIKE OPTICAL LIMITER - A reversible optical energy limiting device comprises a waveguide forming an optical path between an input end and an output end, and an optical energy responsive material located in the optical path for reflecting at least a portion of optical energy received from the input end back toward the input end when the optical energy exceeds a predetermined threshold. The optical energy responsive material does not reflect optical energy when it drops below the predetermined threshold, and thus propagation of optical energy from the input end to the output end is automatically resumed when the optical energy drops below the predetermined threshold. The optical energy responsive material may extend across the optical path an acute angle relative to the longitudinal axis of the optical path so that back-reflected light does not re-enter the optical system. | 07-01-2010 |
20110051231 | LIGHT EXCITED LIMITING WINDOW - An optical power limiter comprises an input optical transmission element, an output optical transmission element, and a power-limiting element disposed between the input and output elements for transmitting optical signals from the input element to the output element. The power-limiting element comprises an optical-limiting solid mixture containing particles of at least one material that produces reversible thermal changes in response to light above a predetermined optical power level, thereby changing the optical transmission properties of the power-limiting element. | 03-03-2011 |
20110164240 | SEA CLUTTER IDENTIFICATION WITH A LASER SENSOR FOR DETECTING A DISTANT SEABORNE TARGET - There is provided a system for detecting distant seaborne objects by an airborne vehicle, including a seeker head having an axis in the direction of flight, a sensor mounted on the seeker's head, the sensor being operative to transmit towards the sea surface a laser radiation beam of selected wavelength and to receive from the sea water surface radiation reflected from the sea water surface and from a seaborne object, and a computing unit for differentiating between the reflection received from the sea water surface and from the seaborne object. A method for detecting distant seaborne objects by an airborne vehicle is also provided. | 07-07-2011 |
20120120975 | DIODE-PUMPED CAVITY - A side-pumped, diode-pumped solid-state laser cavity includes a conductively cooled housing having an opening for pump radiation from a diode array in close proximity to a laser rod. The pump light is absorbed by the rod and excites the laser ions. The cavity includes a thin, diffuse reflector encircling the rod, having a shaped opening for the collection and redirection of the pump light into the rod, and a good heat conductor as the heat sink and heat conductor. A split heat sink inhibits the flow of heat from the pump diodes into the laser rod, and pre-formed air spacings are designed to provide uniform temperature distribution around the laser rod. | 05-17-2012 |
20120155801 | NANOTUBE BASED OPTICAL FUSE DEVICE AND METHOD - An optical fuse or energy-switching-off device includes an optical waveguide having an input section and an output section, the two sections forming a pair of opposed surfaces extending transversely through the axes of the waveguide sections. A substantially transparent material is disposed between the opposed surfaces and comprises an electrically conductive nanotube web immersed in dielectric material, where the nanotubes are not in electrical contact with each other. The substantially transparent material forms a plasma when exposed to optical signals propagating within the optical waveguide with an optical power level above a predetermined threshold, and the plasma damages the opposed surfaces sufficiently to render the surfaces substantially opaque to light propagating within the input section of the optical waveguide so as to prevent the transmission of such light. | 06-21-2012 |
20120257854 | NANOTUBE BASED OPTICAL FUSE DEVICE AND METHOD - An optical fuse or energy-switching-off device includes an optical waveguide having an input section and an output section, the two sections forming a pair of opposed surfaces extending transversely through the axes of the waveguide sections. A substantially transparent material is disposed between the opposed surfaces and comprises an electrically conductive nanotube web immersed in dielectric material, where the nanotubes are not in electrical contact with each other. The substantially transparent material forms a plasma when exposed to optical signals propagating within the optical waveguide with an optical power level above a predetermined threshold, and the plasma damages the opposed surfaces sufficiently to render the surfaces substantially opaque to light propagating within the input section of the optical waveguide so as to prevent the transmission of such light. | 10-11-2012 |
20120287522 | WAVELENGTH-SPECIFIC WIDE IMPINGING ANGLE LIMITER - An impingement angle-independent wavelength-specific limiter includes a stack of wavelength-specific limiters configured to limit impinging light having a plurality of different wavelengths. The stack includes a plurality of wavelength-specific limiters. Each one of the plurality of wavelength-specific limiters is activated by a corresponding wavelength of the impinging light and is configured to limit the corresponding wavelength of the impinging light. | 11-15-2012 |
20130215490 | Responsivity Enhancement of Solar Light Compositions and Devices for Thermochromic Windows - The present invention relates to an optical window-filter including a thermochromic material and a light absorbing material. An absorption of light by the light absorbing material generates heat that causes phase transformation of the thermochromic material. The present invention further relates to a filter for an infrared imaging system having detectors sensitive to radiation in an infrared transmission spectrum. The filter includes a thermochromic material and a light-absorbing material. An absorption of high-power radiation in the infrared transmission spectrum by the light-absorbing material generates heat that causes phase transformation of the thermochromic material to attenuate the high-power radiation while transmitting substantially unaffected low-power radiation in the infrared transmission spectrum. | 08-22-2013 |
20130342888 | Responsivity Enhancement of Solar Light Compositions and Devices for Thermochromic Windows - An optical window-filter includes a thermochromic material and a light absorbing material that can be bonded chemically. Absorption of light by the light absorbing material generates heat that causes phase transformation of the thermochromic material. A filter for an infrared imaging system has detectors sensitive to radiation in an infrared transmission spectrum. The filter includes a thermochromic material and a light-absorbing material. Absorption of high-power radiation in the infrared transmission spectrum by the light-absorbing material generates heat that causes phase transformation of the thermochromic material to attenuate the high-power radiation while transmitting substantially unaffected low-power radiation in the infrared transmission spectrum. | 12-26-2013 |
20140063582 | GLAZING DESIGN WITH VARIABLE HEAT AND LIGHT TRANSMITTANCE PROPERTIES, DEVICE AND METHOD - An energy efficient optical window has different optical properties when irradiated by solar light from front or back side of the window. The window is used to reflect most of the infrared light at summer times, leaving the interior cooler and to absorb most of the infrared light at winter times, making the interior hotter by heat transfer from the hot window pane. Mechanical reversal of the window, inside out, is used to apply the needed version for winter and summer. The window is coated with alternating thin metallic and dielectric layers that transmit most of the visible light while reflecting most of the infrared part of the spectrum when impinged by solar light on one side and transmit most of the visible light while absorbing most of the infrared part of the spectrum when impinged by solar light on the other side. | 03-06-2014 |
20140124715 | ENHANCED RESPONSE PHOTOCHROMIC COMPOSITION AND DEVICE - The present invention relates to optical power-limiting device, and more particularly, to an optical power-limiting passive device and to a method for limiting optical power transmission in lenses and windows, using absorption changes in a novel photochromic composition, having response to infrared light in addition to the conventional response to ultra violet light. This additional response is featuring the use of the novel photochromic composition in places where ultra violet and short wave visible light is absent, or obscured, e.g. using photochromic glasses behind the front window of a car. | 05-08-2014 |
20140220352 | ULTRA VIOLET ENHANCED RESPONSE PHOTOCHROMIC COMPOSITION AND DEVICE - The present invention relates to an optical power-limiting composition for limiting optical power transmission for an entire solar UV spectrum. The composition includes photochromic dye molecules and UV fluorescent nanoparticles in a matrix material. The composition is configured to absorb wavelengths in the entire solar UV spectrum, including wavelengths of 300-340 nm, thereby enhancing photochromic responsiveness of the composition to solar light. The composition includes a first side that receives impinging light and a second side opposed to the first side. | 08-07-2014 |
20140233085 | Reflective Optical Limiter - An optical limiter comprises a glass backing, a glass cover, and a layer of a phase changing material placed between said glass backing and said glass cover, the phase changing material comprising a transparent matrix having embedded particles of material that changes its optical properties due to temperature induced phase change of said material. The optical properties may change from transparent to reflective, from transparent to refractive or from transparent to scattering. The phase changing material is preferably at least one material selected from the group consisting of the elements Antimony, Bismuth, Cadmium, Lead, Tin and Indium and low-melting-point alloys of two or more of these elements. Two or more layers of phase changing materials may be used in a stack configuration, with each of the phase changing materials having a unique melting temperature. | 08-21-2014 |
20140327949 | Window Having Active Transparency Control - An active, transparency-controlled window comprises at least one layer of a material that is transparent to at least selected wavelengths of light; at least one layer of photochromic material having a transparency, to the at least selected wavelengths of light, that can be controllably altered by an activating light; and a controllable source of light that activates the photochromic material to controllably alter the transparency of the photochromic material to the at least selected wavelengths of light. The material that is transparent to at least selected wavelengths of light may be a material selected from the group consisting of glass and plastic. | 11-06-2014 |
20140334026 | LAYERED PHOTOCHROMIC COMPOSITION AND DEVICE - An optical power-limiting passive (self-adaptive) device and method for limiting optical power transmission in lenses and windows, using layers of different photochromic compositions that exploit the full solar ultraviolet (UV) and short visible light spectrum. While a typical single photochromic material is activated by a UV band of wavelengths, e.g. 340 to 380 nm, adding a layer of photochromic material that is activated by an additional band of wavelengths, e.g., 380 to 420 nm, allows the efficient use of a wider band of solar UV and short visible light, e.g., 340 to 420 nm, thus enhancing the photochromic response to solar light. | 11-13-2014 |