Abstract: A light fixture has a source of partially collimated light for emitting light having an axis of collimation. A structured surface has a plurality of prisms that are rendered reflective for reflecting light from the light source out of the cavity. The peaks of the prisms define a surface at least a portion of which makes an acute angle with the axis of collimation.

Abstract: In known Faraday effect current sensors, light is fed into a polarizer, through a coil of field-sensitive optical fiber, and into a polarization measuring device. Such a current sensor can provide greater accuracy of current measurement by using a polarizing optical fiber as its polarizer and splicing the polarizing fiber to the input end of the optical fiber coil. The exit end of the optical fiber coil can be spliced to a second polarizing optical fiber, the other end of which is optically connected to a photodetector. In another embodiment, a mirror at the exit end of the optical fiber coil reflects light back through the coil to second and third polarizing fibers which in turn are optically connected to a pair of photodetectors, thus doubling the Faraday rotation while canceling out reciprocal optical effects.

Abstract: A light extraction film has light extraction structures on one surface and a Fresnel lens for beam shaping on the opposite surface.

Abstract: The present invention is a light fixture having a reflector 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 reflector has a plurality of Fresnel-type structures, wherein at least some of said Fresnel-type structures have a plurality of active faces, for reflecting light in a plurality of directions.

Abstract: An optical fiber connector can be easily and quickly assembled by mounting the end of an optical fiber in a thermoplastic adhesive that is heated to a viscosity of between 1000 and 10,000 cp, has an Adhesion-to-Glass Value of at least 10N, and a Shore D hardness of at least 60 at 20.degree. C. The optical fiber connector lends itself to mass-production techniques and can be reused by heating to liquify the thermoplastic adhesive.

Abstract: A high aspect ratio light fixture has an optical window with a light extraction film therein. The light extraction film has a plurality of linear prisms facing the interior of the light fixture. In one embodiment of the invention the prisms are triangular in shape while in another they are four sided.

Abstract: An optical fiber connector can be assembled without an adhesive using a known combination of a grooved mount and a sleeve that can either grip or release a stripped end of an optical fiber. The mount-sleeve combination is positioned within a housing which is open at one end to receive one or more stripped optical fibers and is formed at its other end with a tiny orifice that is radially aligned with a groove of the mount. After inserting a stripped optical fiber through the mount-sleeve combination and the orifice, the sleeve is allowed to grip the fiber, thus restraining it against longitudinal movement. Because of this restraint, the protruding portion of the fiber can be cleaved or polished along with the adjacent portions of the end cap. The housing preferably is formed by a thermoplastic shroud and a ceramic end cap in which the orifice is formed.

Abstract: A diffractive lens has a plurality of diffractive zones at least one of which has an optical step having an optical height equal to j.lambda. and at least one of which has an optical step having an optical height equal to k.lambda. where .lambda. is a design wavelength of the lens and j and k are unequal nonzero integers. Alternatively stated at least one of the optical steps induces a relative phase shift of 2j.pi. at the back conjugate point between two light rays emerging from a point source at the front conjugate point and striking the lens immediately on opposite sides of the step and at least one of the steps induces a relative phase shift of 2k.pi. at the back conjugate point between two light rays emerging from a point source at the front conjugate point and striking the lens immediately on opposite sides of that step.

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 prisms 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.

Abstract: Polarization-maintaining coupler is made by a biconically-tapered-fused process from two short lengths of an optical fiber, each having a small, oval stress-applying region that substantially contacts the core. The area of the stress-applying region of the optical fiber is less than 10 percent, preferably less than 2 percent, that of the optical fiber and preferably is contiguous with the core. Couplers of highest quality are made from quartz glass fibers having a birefringence between 1 and 3.times.10.sup.-4. It is believed that the principal axes of the oval stress-applying regions of those couplers of highest quality have been collinear or parallel. To permit a coupler to be handled, it can be mounted on a quartz glass substrate with the coupler suspended in air and then potted in a cured elastomer.

Abstract: A single-mode, polarization-maintaining optical fiber has both excellent signal attenuation and resistance to adverse bending effects because (1) its cladding and any portion of the jacket that is within five times the radius of the mode-field in its core have a substantially uniform index of refraction that is at least 0.005 less than that of pure silica, and (2) the index of refraction of the core is at least as great as, but preferably not substantially greater than, that of pure silica. Preferably, the stress-applying region of the fiber is elliptical, and the jacket is pure silica.

Abstract: In the present invention a wide angle safety lens has two major surfaces, each of which is a structured surface. The first major surface has a plurality of parallel linear prisms forming a Fresnel lens that acts like a cylindrical lens having a first negative focal length. The second major surface has a plurality of parallel linear prisms running perpendicular to the prisms of the first major surface and forming a Fresnel lens that acts like a cylindrical lens having a second negative focal length.

Abstract: A single mode optical fiber connector assembly for reducing the need for both positional and angular accuracy is provided. A housing and two single mode optical plugs each containing an optical fiber therein are provided. The housing, is adapted to receive a plug in each end of the housing and is dimensioned to automatically secure the plugs in both positional and angular alignment.

Abstract: A known optical fiber connector includes an elongated mount which is encompassed by a housing that releasably pinches a free end of an optical fiber against a groove in the surface of the mount, thus connecting that free end either coaxially to a free end of another optical fiber or to an opto-electronic element. That connection is made more secure by a block on which the mount can be precisely lodged. The block is formed with a channel extending substantially parallel to the mount and a slide that is slidable in the channel between advanced and retracted positions. When advanced, a protrusion on the slide causes the housing to be deformed, thus enabling a free end of an optical fiber to be positioned in the groove of the mount. When the slide is retracted, the housing returns to its undeformed state and pinches the optical fiber against the groove.

Abstract: An optical fiber connector comprises an elongate plug support member having an interior bore extending between opposed first and second ends thereof, a plug circumscribing a portion of the plug support member adjacent the second end thereof, extending therewithin and also longitudinally outward of the second end. The plug defines an interior bore extending therethrough into communication with the plug support member bore and may be in alignment or in intersecting relation therewith, in respective different types of connectors. An insert is disposed in the plug interior bore and is successively radially circumscribed by the plug and the plug support member. The insert defines an interior passage for receiving an optical fiber and centers same with respect to the plug interior bore.

Abstract: A fiber optic splice includes two cylindrical ferrules of different diameters and having bores parallel to, but offset from, the major axes of the ferrules. The ferrules are inserted into a deformable housing where they rest in a V-groove. When external pressure is applied to the housing it is deformed in a predetermined manner, allowing the ferrules to rotate and when the pressure is removed, the ferrules are held in place.

Abstract: Method and apparatus for reflecting light constrained to travel within a prism light guide such that the reflected light is refracted by and escapes through a selected portion of the light guide wall at a selected angular orientation with respect to the guide.

Abstract: A solar energy concentrator including a thin flexible Fresnel lens for focusing incident solar radiation not normal to the lens onto a target area by refraction. The Fresnel lens is supported or suspended above the target area by a frame and folded along at least one line or region parallel to the refractive prisms of the lens which are generally parallel to the axis of the target area whereby the Fresnel lens opens toward the target area. Thus the Fresnel lens is so positioned so as to allow it to bow and flex under wind loads, gravity and other environmental factors without causing significant deterioration in the efficiency of the system.

Abstract: A prism light guide luminaire of flexible materials which may be collapsed into a flat state for shipping but easily expanded into a tube for use.