Abstract: A DIRCM (Direct IR Counter Measures) system includes a detection and warning apparatus for detecting a missile that might pose a threat on the platform to which said system is allocated, and for generating a warning of its existence. The warning may include data that enable the calculation of the expected direction from which the missile is approaching. The DIRCM system may also include an acquisition device for performing acquisition of the approaching missile in accordance with the data provided by the detection and warning apparatus, and issuing data that may enable the calculation in real time of the updated position of the missile, a fiber laser for generating a laser beam, and a motion and aiming enabled turret, coupled with the laser, for directing the laser beam onto the approaching missile.

Abstract: There is provided a scanning system, including a main housing, and at least one optical wedge (12) rotatable about a shaft means (40) located within the main housing, wherein a laser beam having an optical axis and incident on the optical wedge (12), is refracted at least once by the wedge; characterized in that the shaft means (40) passes through the center of the at least one wedge (12) and that the optical axis of the incident laser beam is substantially parallel to, but laterally offset from, the shaft means (40).

Abstract: A humidity sensor and a quartz crystal microbalance (QCM) therefor, for measuring low humidity levels, and a method for preparing same. The metallic surface of the QCM is electroplated with a hygroscopic layer. The hygroscopic layer preferably includes Manganese. A salt is formed on the hygroscopic layer. The salt is preferably salt of Manganese, and most preferably Manganese Chloride (MnCl2).

Abstract: There is provided a head-up display (HUD) tray harmonization assembly, including a mount alignment jig (MAJ) having a first end and a second end, the first end being connectable to an adjustable tray affixed in an aircraft front cabin at spaced-apart relationship to a front window having a lower edge located adjacent the front end of the aircraft, a telescope connected to the MAJ at, or adjacent, its second end oriented for viewing through the window, a collimator holder having a first portion connectable to the outside wall of the front edge of the aircraft and a second portion extending towards and terminating at least at the lower edge of the window, and a collimator coupled to the second portion of the holder to form a line of sight with said telescope. A method for HUD tray harmonization is also provided.

Abstract: A glass-ceramic material, particularly for elements in laser systems, and a method for preparing same. The glass-ceramic material may be used for an optical fiber for communication systems and laser systems. The glass-ceramic may include gahnite crystals and optionally ?-quartz-like solid solution, or a petalite-like crystals, spinel, and zirconia crystals. The elements may comprise a host material glass-ceramic, where the glass-ceramic is doped with appropriate ions.

Abstract: Light amplifier including an active optical fiber, arranged such that a plurality of fiber sections thereof are aligned and closely packed along a substantially flat plane, thereby defining a light pumping region, and a light introducer having an entry surface and a substantially flat exit surface, the substantially flat exit surface being coupled with the light pumping region, wherein the light enters the active fiber at the light pumping region, through the light introducer, and wherein the device amplifies the light by exciting the active constituents of the active optical fiber.

Abstract: Device for transmitting light at variable intensity, the device including a front variable polarizer, polarizing incoming light at a first selected polarization level, in a first direction and a rear variable polarizer, optically coupled with the front variable polarizer, polarizing light exiting the front variable polarizer at a second selected polarization level, in a second direction, wherein the first selected polarization level and the second selected polarization level are substantially zero, when no substantial electric power is applied respectively, to the front variable polarizer and the rear variable polarizer.

Abstract: The invention provides a system for varying the transmittance of light through selected portions of a media on which images are displayed, the system including an image display panel, an image display source for projecting images on the media, LC-based, variable transmittance optical (VTO) media, a light sensor for measuring ambient light, and a signal generator connected to the VTO media for applying voltage to portions of the media at levels determined and controlled by the sensor, whereby the transmittance of light through the portions of the media is varied in accordance with the prevailing ambient light. A method is also provided.

Abstract: The invention provides a multi-layered imaging device for three-dimensional image display, including a plurality of two-dimensional layers superposed in the third dimension, each of the layers having two major surfaces and at least one peripheral edge, the layers being made of a material selected from the group of non-conventional, polarizer-free liquid crystal materials including polymer-dispersed liquid crystals (PDLC) and derivatives and combinations thereof, wherein the exposure of at least one of the layers to illumination allows the transmission of light with minimal losses, facilitating utilization of a maximal number of layers for imaging a three-dimensional display.

Abstract: The invention provides a numerical aperture limiter for an optical thermal imaging system, comprising at least one pair of wedge-like prisms made of a transparent material having a known index of refraction, the prisms of the pair being disposed in close mutual proximity and in opposite orientation with the narrow end of one prism adjacent to the wide end of the other prism, the prism surfaces facing one another of the pair of prisms being spaced apart from one another by a distance at least equal to the wavelength of the light used by the imaging system, with the vertex angle of each one of the prisms being a function of the desired numerical aperture and the index of refraction.

Abstract: The invention provides a holographic optical device, including a light-transmissive substrate; a first holographic optical element carried by the substrate; at least one second holographic optical element carried by the substrate laterally of the first holographic optical element, and at least one third holographic optical element carried by the substrate laterally displaced from the first and second holographic optical elements; wherein the center of at least one of the first, second or third holographic optical elements is located outside a single, straight line.

Abstract: The invention provides a laser system for producing a high energy amplified laser beam output from an oscillator producing a wave front of low energy laser beam, the system including at least one amplifier positioned to receive the low energy laser beam for amplification via a first polarizer; a second polarizer, positioned along the axis of the amplified beam at the output side of the amplifier, for allowing a first fraction of the beam to pass therethrough and for reflecting a second fraction of the beam from an output surface of the polarizer, the second fraction constituting the output of the system; a retroreflector, associated with a quarter wave plate, oriented to receive the first fraction and to reflect it back toward the second polarizer, and reflecting means for reflecting the reflected first fraction toward the first polarizer to be reflected toward the amplifier for further amplification and to be reflected off the output surface of the second polarizer together with the second fraction.

Abstract: The invention provides a device for linear scanning, including at least one reflecting element whereby an incident beam of light undergoes at least two reflections; at least one optical system comprising an objective capable of forming an image of an object, the objective, depending on the respective direction of the light beam, defining a pre-objective scanning space and a post-objective scanning space; a mounting structure for the at least one reflecting element; drive means for causing the mounting structure to perform a movement; and a light-detecting element for detecting the incident beam of light, or an element for producing light, wherein, with light-detecting, scanning takes place in the post-objective space, and with light-producing, scanning takes place in the pre-objective space.

Abstract: The invention provides a method for multi-pixel imaging of a scene, using a single detector associated with a time-delay arrangement, the method including the steps of producing an image of at least part of a remote scene in a defined image plane; receiving the scene as imaged on the image plane and conveying it image pixel by image pixel through a plurality of light-conveying means to a single detector while introducing a time-delay, whereby the image pixels arrive at the single detector in a sequential order, and using an electronic logic to reconstruct the image from the time-delayed image pixels received by the detector. The invention also provides a system for implementing the described method.

Abstract: The invention provides a system for varying the transmittance of light through selected portions of a media on which images are displayed, the system including an image display panel, an image display source for projecting images on the media, LC-based, variable transmittance optical (VTO) media, a light sensor for measuring ambient light, and a signal generator connected to the VTO media for applying voltage to portions of the media at levels determined and controlled by the sensor, whereby the transmittance of light through the portions of the media is varied in accordance with the prevailing ambient light. A method is also provided.

Abstract: The invention provides a method of bonding an optical element within an enclosure, the method comprising providing an optical element within an enclosure having interior walls configured and sized to surround the exterior walls of the optical element with clearance, so as to form a space therebetween; introducing into the space members having a cross-section substantially the same as the cross-section of the space at the locations of the members; filling the space with adhesive which does not adhere to the members, and removing the members, forming air-filled voids which cause the reduction of stress in the optical element when its temperature changes. The invention further provides an optical system to be used in the described method.

Abstract: The invention provides a near-field photochromic device for a supra-density optical memory, comprising a scanner carrying a data storage medium, an optical head having a tip, to be used for recording, readout and erasing, and located in close proximity to the data storage medium, and at least two lasers, alternatingly optically alignable with the optical head, wherein the data storage medium is a film consisting of a photochromic compound and wherein the distance between the tip and the data storage medium is within the limits of the near field of the optical head.

Abstract: The invention provides a thermal switch, including a frame made of electrically insulating material, defining the perimeter of a cell fillable with liquid crystal (LC); first and second plate-shaped electrodes, each having an inside surface and an outside surface and being attached along the periphery of the inside surface on opposite sides of the frame, defining surfaces of the cell; first and second covers made of electrically insulating material, each attached to the outside surface of one electrode, the inside surface of at least a portion of each of the electrodes being treated to obtain anchoring of the orientation of LC molecules in a direction parallel to the plane of the electrode, resulting in improved performance of the switch.

Abstract: The invention provides a circuit arrangement for igniting gas discharge flash tubes including a gas discharge flash tube having two-spaced-apart electrodes, a pulse forming network and a voltage generator for supplying ignition pulses and tube burning pulses during simmer mode, the arrangement having a resonant circuit connected in circuit between the electrodes and the voltage generator, wherein the voltage generator provides the resonant circuit with AC high frequency voltage for producing gradually increasing amplitudes of an AC voltage until ignition voltage is achieved and for supplying AC voltage of a lower level in comparison to the level of the ignition voltage, for sustaining the burning of the tube during the simmer mode.

Abstract: The invention provides an optical tracing system for measuring elevation of a reference body above a reference surface, comprising a laser transmitter radiating a light beam in a downward direction; an optical unit for imaging the radiation reflected from said body and said surface on a detector; filtering means for separating light originating from said laser from background illumination, and signal processing means for identifying said reference body and for measuring the elevation thereof from said surface.