Abstract: A sleeve (21) includes a core (22) of transparent synthetic resin and a cladding (23), also of transparent synthetic resin, having a smaller refractive index than the core. The core includes an optical waveguide (24) extending in an optical axial direction to taper in a conical shape and a lens (27) formed at the large diameter end of the waveguide. The lens receives light and converges it. There is a circular flange-like guide integral to the outer wall in the vicinity of the lens. The cladding (23) is formed concentrically with the core in intimate contact with the outer wall of the core. The configuration improves the transmission efficiency of light and contributes to cost reduction of the sleeve.

Abstract: Disclosed is a scanning optical system, which is provided with a light source portion, a deflector, which deflects a beam emitted from said light source portion, and a scanning lens for converging the beam deflected by the deflector onto a surface to be scanned. The scanning lens has a positive power as a whole, and includes a plurality of refractive lens elements. Further, a diffractive lens structure is formed on at least one surface of one of the plurality of lens elements of the scanning lens. The diffractive lens structure is defined by an optical path difference function that is asymmetrical with respect to the optical axis of the refractive lens in the main scanning direction, which is counterbalanced with an asymmetrical movement of a deflecting point, compensating a lateral chromatic aberration.

Abstract: Optical systems for use with reflective LCDs (8,9,32,34,36) are provided. The systems include a polarization beam splitter (5) which can be composed of polarization beam splitting cubes (26) having sheet polarizers (30) and/or half wave plates (28) at their mating surfaces. By orienting the half wave plates (28) so that they convert S polarization to P polarization and P polarization to S polarization, the polarization beam splitter (5) can provide a high contrast ratio at a viewing screen between light from the “on” and “off” pixels of the reflective LCDs (8,9,32,34,36).

Abstract: A diffraction grating that achieves high diffraction efficiency at all polarizations for optical signals at telecommunications wavelengths is provided. The diffraction grating has a substrate and a plurality of reflective faces oriented at respective blaze angles &thgr;b spaced along the substrate surface, with the blaze angles substantially differ from the Littrow condition. Each reflective surface is supported by a support wall connected substantially with the substrate surface. The grating may be used in interference orders greater than first order and may diffract signals with low polarization-dependent losses in addition to high polarization-averaged efficiency.

Abstract: In a method for the coating of substrates made of plastic, with a light-reflecting layer, preferably an aluminum layer, and another layer placed between the substrate and the light-reflecting layer, the additional layer, which has a high barrier effect to substances which migrate or evolve gases from the plastic, is a highly crosslinked hydrocarbon layer, a silicon dioxide, silicon nitride, or silicon oxynitride layer, with a thickness of at least 15 nm, wherein the carbon content of the barrier layer is <15%.

Abstract: A lightweight contact holographic sight includes a housing and a base which form a compartment containing a laser diode, an associated power source, and optical elements including a mirror, an off axis collimator, a reflection grating, and an image hologram of a reticle pattern, wherein the optical elements are arranged within the compartment to direct and fold the laser beam in a substantially generally vertical path. In one aspect of the invention, an elevation and windage adjustment mechanism is provided to rotate the reflection grating about two orthogonal axes to thereby adjust the projected reticle pattern for windage and elevation. In another aspect of the invention a removable battery compartment including a cam surface which is releasably contacted by a cam lever arm pivotally mounted on the sight housing or the base to allow for quick tool-less removal of the compartment for battery replacement.

Abstract: A symmetric relay system for endoscopes includes an optically-aligned pair of elongated concavo-convex rod-type lenses formed from crown glass, to the convex end surface of each of which a meniscus-shaped flint lens is cemented. The concave ends of the rod lenses are disposed to face the intermediate images of the relay system, and the convex ends to face the aperture of the relay system. A pair of achromatic lenses, each formed of a pair of lens elements x, y, are disposed adjacent and in optical alignment with the respective concave ends of the rod lenses between the concave rod ends and the intermediate images. Each achromatic lens fulfills the condition n x/ny=vx/vy. Apochromatic glass combinations may be used in the rod lenses to significantly reduce the secondary spectrum.

Abstract: A description is provided of an optical information recording and reproducing apparatus. The apparatus comprises: a holographic memory made of a photorefractive crystalline material; a support portion for detachably supporting the memory; a reference beam supplying portion for supplying a coherent reference beam of a first wavelength incident on the memory; a signal beam generating portion for supplying a coherent signal beam of the first wavelength, which is modulated in accordance with image data, incident on the memory, intersecting therein the signal beam with the reference beam, and generating a three-dimensional interference pattern of the beams; a detecting portion for detecting a diffracted light from a refractive index grating of the interference pattern in the memory, due to irradiation of the reference beam; and a medium position adjusting portion for moving a position of the support portion in accordance with a signal corresponding to positioning images from the detection portion.

Abstract: An optical head comprises a light path alteration member (first surface of a first transparent substrate), a first grating element and a second grating element arranged in that order in a light path between a light source and an optical disk. A beam emitted by the light source passes a collimated lens, is deflected by total reflection from the light path alteration member, and enters the first grating element. Diffracted light enters a second grating element, and is focused on a recording medium by an objective lens. Wavelength variations in light diffracted by the first grating element and wavelength variations in light diffracted by the second grating element at least partially cancel each other out. Thus, a thin optical head for an optical recording medium is provided.

Abstract: A motorcycle rear view mirror assembly for addition to motorcycles and like vehicles providing a view of both the rear sides, and directly behind and adjacent to the rear of the motorcycle which will increase the safety of the operator when changing lanes and will make the rider aware of vehicles approaching too close behind them. The device features a first mirror positionable to an angle to reflect the area to the side of a motorcycle into the view of the rider and a second mirror attached to said assembly adjacent to an outside edge of first mirror and a provision for adjustment of the face of the second mirror toward the inside edge of the first mirror to an operative angle between 3 and 25 degrees.

Abstract: A grating device with a substantially polarization-independent diffraction efficiency is disclosed. The grating device is preferably a surface grating that can be produced by ruling or holographically, and includes at least two different grating elements with the same grating period, but different modulation depths or blaze angles. The blaze angles and the illuminated areas of the respective grating elements can be selected to produce a substantially polarization-independent and optionally also wavelength-independent response of the grating device.

Abstract: The optical switch comprises a substrate, a planar waveguide circuit, an index-matching liquid, a working fluid and a displacing device. The planar waveguide circuit is supported by the substrate. The planar waveguide circuit and the substrate collectively define a trench that includes a first trench region and a second trench region adjacent the first trench region. The second trench region has a width greater than the first trench region. The planar waveguide circuit includes a first waveguide and a second waveguide. The waveguides intersect at the first trench region and are positioned such that light traversing the first waveguide enters the second waveguide when an index-matching material is present in the first trench region, and is otherwise reflected by said the first trench region. The index-matching liquid is located in at least part of the first trench region. The working fluid is located in the second trench region.

Abstract: An optical semiconductor module has a housing having an opening, and an optical semiconductor element is set in the housing. An optical fiber that penetrates the opening is disposed. The optical fiber is allowed to perform optical transmission between the optical semiconductor element and elements arranged outside the housing. The opening is sealed with a photo-curing resin, and a transparent plate is arranged between the photo-curing resin and the outside of the housing.

Abstract: A simplified hand held stereoscopic imaging system in which stereoscopic recording and three-dimensional playback of objects viewed with the device is provided with a single recording element and a single playback element.

Abstract: The present invention provides a strictly non-blocking WDM cross-connect that utilizes a relatively small number of wavelength interchangers. In accordance with one embodiment, the WDM cross-connect utilizes n1k1 wavelength interchangers, where n1 is an integer equal to the number of wavelengths carried on an input optical fiber associated with the WDM cross-connect and k1 is the total number of input optical fibers to the WDM cross-connect. Each of the wavelength interchangers is connected to exactly one input port of the fabric and each input port of the fabric is connected to exactly one wavelength interchanger. The input optical fibers of the WDM cross-connect are connected to k1 optical switches of the cross-connect that separate out the n1 wavelengths onto n1 optical fibers, which are input to respective wavelength interchangers. Therefore, each wavelength interchanger receives exactly n1 optical fibers.

Abstract: The present invention provides an apparatus for cleaning an optical fiber ribbon without splitting the ribbon. The apparatus comprises a first element that has a channel formed therein, which preferably has a width that is substantially equal to the width of an optical fiber ribbon. A ribbon is cleaned by disposing it in the channel and by pulling it through the channel while applying a force to the top surface of the ribbon. The force may be applied, for example, by a user who applies a cleaning cloth to the top surface of the ribbon as it is pulled through the channel. The contact between the channel, the cleaning device and the exterior surface of the ribbon effectuates removal of foreign material from the exterior surface of the ribbon. In accordance with the preferred embodiment, the apparatus further comprises a second element. The second element includes a bottom surface that is disposed over the channel when the first and second elements are placed in their operative positions.

Abstract: A diffraction grating for generating a plurality of beams includes a plurality of gratings. The plurality of gratings are formed to have an axis of symmetry perpendicular to the direction in which a beam is divided on a surface of diffraction grating and include at least two gratings having different fundamental cycles. The plurality of gratings are formed such that they have an axis of symmetry perpendicular to the direction in which a beam is divided on a surface of the diffraction grating, for generating a plurality of beams. The fundamental cycle increases as a function of the distance from the axis of symmetry, and therefore aberration in the periphery of scattering light may be reduced.

Abstract: A method according to preparing an integral image from an interwoven image is provided. The interwoven image is prepared by interweaving at least two source images which have been divided into cells which themselves have been divided into image elements. By interweaving the image elements within each cell and forming an array of cells, an integral image is formed when the array of cells is viewed through a viewing screen. 3-dimensional, moving or motion, and images which are combinations thereof are formed with the present device. The method can be used in electronic display devices as well as on non-electronic services to form integral images. A 3-dimensional image formed by the present device will generally have a portion which appears to project above the surface of an overlaying viewing screen. A quality control method for the manufacture of three-dimensional integral image devices and for the selection of viewing screens is also provided herein.

Abstract: A reflective liquid crystal display device (LCD) (40) includes: a substrate (60), a reflecting layer (61), a liquid crystal layer (62), an electrode layer (63), a color filter layer (64), an upper substrate (65), and a polarizer (66). The reflective liquid crystal display device further includes a holographic field lens (67). By providing the holographic field lens, the LCD can be used with a closely placed, offset light source (41), since the holographic field lens simultaneously concentrates light incident on the LCD and redirects it in a preferred direction. The holographic field lens can be provided within the structure of the LCD.

Abstract: A see-through retroreflective structure includes a transparent polymeric film, an array of retroreflective elements attached to the polymeric film, and an array of apertures through the retroreflective structure within the array of retroreflective elements. In one embodiment, the retroreflective structure includes a metalized reflective layer formed on the transparent prism elements and a support layer, such as a fabric, is attached to the metalized reflective layer. The method includes providing a transparent polymeric film. An array of retroreflective elements is attached to the polymeric film. The array of retroreflective elements and the transparent polymeric film are perforated through the retroreflective structure to form an array of apertures, thereby forming a retroreflective structure. The apertures are of sufficient size and spacing to provide a see-through capability.