Abstract: A beam splitter formed by laminating a plurality of optical films on a glass substrate having a refractive index of 1.51.+-.0.10. The optical films are first, second, third, fourth, and fifth layers laminated in this order from the glass substrate. The first layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.05-0.15; the second layer has a refractive index of 1.68.+-.0.10 and an optical film thickness of 0.01-0.10; the third layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.50-0.60; the fourth layer has a refractive index of 2.23.+-.0.10 and an optical film thickness of 0.25-0.35; and the fifth layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.25-0.35. The optical film thickness means a relative value represented by n x d/.lambda. where n denotes a refractive index; d denotes an actual film thickness, and .lambda.denotes a wavelength deciding the center of a wavelength band.

Abstract: An optical component welding apparatus for welding together first and second optical components each having an optical axis and a contact surface. The apparatus includes an X--Y stage for fixing the first optical component and aligning the optical axis of the first optical component in an X-axis and Y-axis direction. A fixing disk has a plurality of apertures extending radially and intersecting one another at a center of the fixing disk with respect to the radial direction, and includes a clamp for fixing the second optical component in the center of the fixing disk with respect to the axial and radial directions thereof such that the contact surface of the second optical component faces the contact surface of the first optical component.

Abstract: A method and apparatus are provided to allow the operator of a vehicle wishing to change traffic lanes to temporarily scan an angle of the passing lane which is in his or her "blind spot", i.e., an area outside the normal angle of viewing of a conventional flat side rear view mirror. The invention is also useful to divert the headlight reflection from a vehicle in a passing lane out of an operator's eyes. Accomplishment is through temporary pivotal movement of the side mirror to shift the mirror viewing angle from the position at which it had been preset by the operator for normal driving.

Abstract: A holographic thin rear exterior lamp for a vehicle including a light pipe (11) having first and second opposing surfaces (11a, 11b), a rear exterior lamp hologram (13, 113) attached to one of the first and second surfaces of the light pipe, a polarization rotating retarder film (16, 116) attached to one of the first and second opposing surfaces oppositely from the rear exterior lamp hologram, a light source (17, 19) for providing a substantially collimated beam, a transmission hologram (15) disposed on one of the first and second surfaces of the light pipe for coupling the substantially collimated beam into the light pipe such that a portion of the substantially collimated light propagates by total internal reflection within the light pipe, the rear exterior lamp hologram and the polarization rotating retarder film. The polarization rotating retarder film is configured to impart a substantially halfwave retardance to internally reflected light that passes twice therethrough.

Abstract: A diffractive optical element, ("DOE"), and particularly a diffractive lens having annular zones about an optical axis and known as a Fresnel zone plate or kinoform lens, is athermalized so that its effective focal length ("EFL") does not shift substantially with temperature over a temperature range by, respectively, increasing and decreasing the zone widths with respect to widths which are optimized to focus at the EFL at room temperature. Half of the zones (alternate, adjacent zones) provide the correct EFL for the expanded condition of the lens at the hot end of the temperature range; the other half of the zones provide correct EFL for the contracted condition of the lens at the cold end of the temperature range.

Abstract: A catadioptric lens system may be operated in the telephoto mode to allow images of distant objects to be formed with large image plane magnification and be part of a camera body wherein a rear reflective section of the catadioptric lens system is provided by a front face of the camera body which has a clear aperture centered about the optical axis. An image is focused at the film plane. The catadioptric lens system has a diffractive/refractive hybrid singlet lens which corrects off-axis aberrations and decreases the overall lens length. The front surface of the lens defines an asphere. The back surface has a diffractive lens with annular blazed zones. The back surface also has an inner portion which is reflective and may have the same curvature as the transmissive section of the singlet (the back surface base curve of the from which the blazed zones extend). The lens system provides catadioptric imaging (sometimes called contracurrent or katoptric imaging) at the film plane.

Abstract: A new vehicle mirror viewing system which is designed for rear view mirrors mounted exteriorly of a vehicle and allows a driver to either view the mirror or an image transmitted from the mirror to a viewing screen mounted interiorly of the vehicle. A fiber optic transmission cable is utilized in conjunction with a two-way mirror to transmit the reflected image from the mirror to the viewing screen. The cable utilizes a large bundle of fiber optic cables, and the ends of the cables are mounted in small blocks which allow only small pixels of light to be transmitted from an image passes through the two-way mirror. With the ends of the cables mounted in arrays within transducers, a composite image can be transmitted from a rear surface of the rear view mirror to the viewing screen.

Abstract: A Fourier mask includes a base plate, an aperture plate having a pair of cross hairs fixedly mounded on the base plate and a pair of four bar linkages, each four bar linkage being made up of a pair of parallel cross bars and a pair of parallel mask bars pivotally interconnected end-to-end in a closed loop configuration. Each cross bar in each four bar linkage is pivotally mounted on the base plate, the four bar linkages being arranged on the base plate such that the mask bars in one four bar linkage are at right angles to the mask bar in the other four bar linkage and each pair of parallel mask bars is symmetrically disposed about one of the cross hairs. By pivotally moving either or both sets of cross bars on the base plate, the spacing between the parallel mask bars in either a both sets of mask bars can be changed as desired.

Abstract: A device is provided including a flexible sheet having extents encompassing at least a circular area, said flexible sheet doubled-over upon itself through the center of the circular area such that the resultant respective halves of said circular area overlap and form a semicircular field of view; and a sleeve for maintaining the overlapping configuration of said doubled-over flexible sheet, yet allowing said flexible sheet to be displaced about the center of said circular area within the doubled-over configuration. In a particular embodiment, the encompassed circular area of said flexible sheet has at least one light-transmissive region within the circular area, such that transmission of light through the aforementioned field of view can be varied by said displacement of the flexible sheet within said doubled-over configuration. Such embodiment, when employing a polarizing sheet as said flexible sheet, can be used as a variable light transmission device.

Abstract: A two-photon process for writing to a holographic recording medium comprising a photorefractive material doped with an excitation dopant selected from rare earth ions and an ionization dopant selected from transition metal ions or rare earth ions.

Abstract: An output scanner for recording an image on a radiation sensitive medium comprises an at least part cylindrical support which carries the medium in use, the medium facing radially inwardly. A scanning unit is positioned radially inwardly of the support and has a generator for generating a plurality of modulated radiation beams, the beams being modulated with respective image information, and a reflector for reflecting the two beams onto the medium at respective, different positions. Optics focus the beams onto the medium. Motors cause relative rotation and traverse movement between the scanning unit and the support about and along the axis of the support respectively.

Abstract: A polarizing beam splitter includes: an optically isotropic substrate; a layer of birefringent material formed on top of said optically isotropic substrate; and a periodic pattern of ridges and grooves formed on a surface of said optically isotropic substrate to make a grating; and a refractive index equal to either the refractive index of the birefringent material for ordinary light or the index for extraordinary light, said grooves being filled with the material.

Abstract: In a display section, a plurality of pixels of minimum display units to display a hologram phase distribution are arranged to thereby construct a cell to display one pixel of a 2-dimensional image, and cells are further two-dimensionally arranged to thereby construct a display image plane. 2-dimensional image data and hologram phase distribution data from an input section are given to a display data forming section. Corresponding 2-dimensional image data and a hologram phase distribution are displayed in a display region of a display section, thereby producing hologram data for allowing a solid image to be recognized by the optical wave front conversion. A display control section executes a display control for allowing the 2-dimensional image data and hologram data from the display data forming section to be displayed in the display section.

Abstract: A device and technique for the passive real-time control of effective emivity, color, and camouflage, the device utilizing surfaces which are interposed between a target and an observer at a viewing position with a predetermined angular resolution. Effective surfaces are utilized, including at least one set of movable surfaces, the effected surfaces having a predetermined surface characteristic, such as emissivity, color, or camouflage pattern. An assembly contains all surfaces relative to each other such that the front and back surfaces are seen by the viewing position as stationary. A drive assembly allows movable surfaces to move.

Abstract: A multi-beam laser exposure unit of the present invention includes a light beam deflector for deflecting a light beam in a predetermined direction, a plurality of laser devices, a pre-optical system, including a glass lens and a plastic lens, for converting a cross sectional shape of a light beam emitted from the respective laser devices to a predetermined shape, and a post-deflection optical system, including two lenses for image-forming each light beam deflected by the deflector to be scanned on a predetermined image surface at a uniform speed. The power of the two lenses of the post-deflection optical system is defined to be positive in a direction parallel to a rotational axis of reflective surfaces of the deflector. Also, at least one lens surface of these lenses is formed not to include a rotational symmetrical surface.

Abstract: Dispersive dielectric mirror exhibiting a monotonic, more particularly nearly linear group delay versus frequency function over a wide frequency range within the high reflectivity band of the mirror, which group delay is introduced on electromagnetic wavepackets, more particularly, on light pulses, when the electromagnetic wave is reflected on the mirror. The dispersive dielectric mirror can be well applied for dispersion control in electromagnetic impulse technique from microwave frequencies to X-rays, more particularly, in ultrashort-pulse-laser technique and its applications. One of the concrete applications of the dispersive dielectric mirrors is to solid-state-laser intracavity dispersion control of femtosecond pulse solid-state-laser oscillators instead of using of prism pairs. The laser built in this way is more compact, reliable and user friendly than its prism-pair-dispersion controlled predecessors.

Abstract: A composite hologram incorporates a plurality of hologram tiles arranged for display, each of the hologram tiles formed by exposing each of a plurality of different unexposed photographic plates simultaneously to light scattered by an intermediate hologram using a conjugate complex of a first reference wave from a coherent light source and to a second reference wave from the coherent light source.

Abstract: A light scanning optical system includes a plurality of lasers spaced from each other and a deflector which deflects laser beams emitted from the lasers so that the laser beams scan a recording medium while forming beam spots on the recording medium spaced from each other in the scanning direction. A plurality of reflecting surfaces which are provided on a single base body to reflect the respective laser beams toward the deflector at different angles is disposed on the optical path of the laser beams between the lasers and the deflector.

Abstract: A multi-purpose objective for use in a compound microscope wherein the microscope has an eyepiece and a multi-purpose processing element in the back focal plane or Fourier plane of the objective and an aperture or slit for the light source situated in the front focal plane or conjugate Fourier plane of the condenser. An aperture specimen stage is disposed between the condenser and objective lenses. The multi-purpose light processing element has a plurality of light processing regions upon a selected region of which the image of the aperture slit is formed. The aperture element is moveable relative to the multi-purpose light processing element so as to direct light onto the selected region of the multi-purpose processing element.

Abstract: An optical filter arrangement comprises at least two optical filter elements including a transparent substrate and an optical coating typically comprising at least two overlying optical thin films. The coating defines a first patterned area and a second surround area bordering the first area. The first area has substantially the same optical transmittance characteristics as the second area and different optical reflectance characteristics over at least a portion of the visible spectrum. The distinction between the first area and the second area is visually perceptible when viewed from one side of the optical filter arrangement and is substantially visually imperceptible when viewed from the opposite side of the optical filter arrangement. As a result, a coloured pattern or logo is only visible when viewed from one side of the filter arrangement. The invention extends to a method of forming such an arrangement.