Abstract: The light box is provided with a case having arranged therein a reflector directed to the front wall to be illuminated from the rear. The reflector surf ace has a concave curvature. An elongated light source is arranged in the center of the case. The reflector, in the central area thereof, is covered by an optical film having a structured surface directed to the light source. This structure consists of immediately adjacent V-shaped grooves, being parallel to each other and running transverse to the extension of the light source. By total reflection on the structured surface of the transparent optical film as well as by reflection on the reflector surface of the reflector, the light of the light source incident on the reflector is reflected in the direction of the back-lit front side of the light box. This arrangement provides for improved and more-uniform light distribution.

Abstract: A depolarizer operates by splitting light traveling along an optical fiber into two sub-beams. One of the sub-beams is inserted into a recirculation loop, where it has its polarization state altered. The light in the recirculation loop is then reinserted into the fiber at a position prior to that at which the splitting occurred.

Abstract: A plastic film has a series of grooves the interiors of which are rendered light absorbing to form a light-collimating film.

Abstract: The lamp has a case with a light exit opening. A reflector is arranged on the rear wall of the case facing the light exit opening, in front of which an elongated light source is arranged. Between the light source and the light exit opening there is a flexible optical film, stable in shape, with a smooth surface and a structured surface. The smooth surface faces the light exit opening, while the structured surface is directed toward the light source. The structure consists of a plurality of V-shaped grooves extending in parallel to each other and transverse to the longitudinal extension of the light source, the grooves lying immediately side by side. The optical film extends only in that area in which the light source emits light directly toward the light exit opening.

Abstract: A coil of optical fiber can be self-supporting by bearing a layer of brittle thermoplastic adhesive that adheres adjacent convolutions of the fiber together. Because it is self-supporting, the coil needs no hub so that either end of the fiber can be unwound. Preferred thermoplastic adhesives are marketed in the optical industry as blocking waxes.

Abstract: The present invention is a light fixture having a catadioptric lens designed to discard preselected amounts of light from a light source. The percentage of the light discarded will vary over the surface of the reflector in order to provide a predetermined output intensity distribution.

Abstract: A back-lit display having a window including a light-collimating film. The light-collimating film has an opaque material on a surface thereof. A material of a predetermined color is on the opaque material in registration therewith.

Abstract: A passive railroad crossing warning device has two input optical windows that receive light from the headlight of an oncoming locomotive. The light is redirected to an output optical window where a combiner causes it to exit at a predetermined angle to make it visible to motorists approaching the railroad crossing.

Abstract: An ophthalmic lens exhibiting diffractive power has a plurality of diffractive zones and smooth surfaces. The zones are arranged such that R.sub.0.sup.2 does not equal R.sub.1.sup.2 -R.sub.0.sup.2 where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.

Abstract: An optical fiber distribution module has a panel formed with a plurality of parallel lands having undercuts for releasably attaching a plurality of optical fiber connectors, each of which forms a bridge across the panel. The lands have sufficient length to permit two of the connectors to be attached to the same lands with a jacketed optical fiber from each of said connectors passing beneath the bridge defined by the other connector. When a large number of the connectors are attached to the panel, the passage of some optical fibers beneath such bridges helps to organize, route, and identify the interconnected optical fibers.

Abstract: When two hollow tubular light conduits are interconnected at a miter joint, beamed light can be redirected from one of the conduits to the other by a thin transparent prismatic element that is mounted to extend along the plane of the miter joint. When the interconnected conduits are acting as a luminaire, the miter joint can be fully illuminated by the transported light. A luminaire of unlimited length can be obtained by mounting a plurality of lamps and parabolic reflectors along a transparent hollow tubular light conduit and redirecting light from each lamp to be transported along the axis of the conduit in both directions.

Abstract: A multifocal ophthalmic lens has diffractive power produced by a plurality of concentric zones. The zones have radii that meet the conditionR.sub.0.sup.2 is not equal to R.sub.1.sup.2 -R.sub.0.sup.2where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.

Abstract: An optical fiber switch has a substrate with a straight groove into which the free ends of two optical fibers are pushed into abutting relation to permit signals incoming on one of the fibers to be transmitted to the other. Preferably, the switch is a 2.times.2 fiber array. In one 2.times.2 switch, a substrate has two mutually perpendicular surfaces, each formed with a pair of grooves, and all four optical fibers are simultaneously pushed into one set of grooves to connect the fibers in one way, or pushed into the other set of grooves to switch the alignment. In a different 2.times.2 switch, a substrate has a central, longitudinal passageway that is square in cross section, and the grooves are provided by the four corners of the passageway.

Abstract: A light fixture has an optical cavity having a first region and multiple additional regions, each of the additional regions, each of the additional regions having an optical window. Light from a light source in the first region is directed out of the optical windows in each of the additional regions.

Abstract: A light fixture has a housing having an axis and a light source for detecting light into the housing along the housing axis. A first section of the housing occupies a first portion of the housing's perimeter and includes a light guide material. A second section of the housing occupies a second portion of the housing's perimeter and includes light extraction structures and a Fresnel lens for beam shaping.

Abstract: A prior optical fiber connector includes an elongated mandrel of substantially uniformly elliptical cross section that is encompassed by a resiliently deformable housing which, in its relatively undeformed state, can optically interconnect two optical fibers by urging their ends against a straight longitudinal groove in the surface of the mandrel. The interconnection can be made more easily when there is, either integral with or around the housing, an envelope incorporating a pair of second-class levers which, when squeezed together by ones fingers, deform the housing. The extremities of the levers can be formed to permit the connector to be releasably attached to a patch panel or to an optical fiber distribution module.

Abstract: A multifocal ophthalmic lens has diffractive power produced by a plurality of concentric zones. The zones have radii that meet the condition R.sub.0.sup.2 <R.sub.1.sup.2 -R.sub.0.sup.2 where R.sub.0 is the radius of the central zone and R.sub.1 is the radius of the first annular zone.

Abstract: Apparatus for determining the displacement or position of an object comprises a light source and a light receiver for receiving light transmitted from said light source, and a fiber optic conduit of Y-shaped configuration having the end of one arm thereof positioned adjacent said light source and the end of the other arm positioned adjacent said light receiver, said conduit arms forming a common bundle of optically conducting fibers in the base of said Y, some of which are transmitting fibers for conducting light from said light source to a surface of the object and some of which are receiving fibers for conducting light reflected from the surface of said object to said light receiver so that the conduit is normally objective to conduct light from said light source and to conduct reflective light impinging on an end face of said common bundle to said light receiver.

Abstract: A single-mode, single-polarization optical fiber ("PZ fiber") can have a large single-polarization wavelength bandwidth when .eta. (as herein defined) for one symmetry axis is positive when calculated from the refractive index profile determined with one of two orthogonal orientations of polarized light and is negative when calculated from the refractive index profile determined with the other orientation, and for each other symmetry axis of the novel optical fiber .eta. is positive for both orientations of plane polarized light. Preferably the absolute values for .eta. when positive and .eta. when negative are about equal for said one symmetry axis. A preferred PZ fiber can be formed by depositing siliceous layers onto the interior surface of a hollow substrate tube of quartz to provide a preform. After forming two parallel flat faces in its outer surface, the preform is pulled to form a PZ fiber having an ellipitcal stress-applying region.

Abstract: A thin, flexible film made of a transparent polymeric material including a structured surface and an opposite smooth surface, wherein light striking either surface, within certain angular ranges, is totally internally reflected. The structured surface includes a linear array of miniature substantially right angled isosceles prisms arranged side-by-side to form a plurality of peaks and grooves. In addition, the perpendicular sides of the prims make an angle of approximately 45.degree. with the smooth surface, and when the film is curled the smooth surface lies in a smooth continuous arcuate curve without materially affecting the performance of the film. Because of the film's flexibility and its ability to totally internally reflect light, it may be utilized in a variety of ways, for example, as a collector of solar energy or as a light conduit. The performance of the film may be manipulated to permit controlled light leakage.