Abstract: A graded index, multimode optical waveguide. The waveguide is characterized by a graded profile region, followed by an abrupt drop in index, then a region of constant index. At predetermined intervals, the fiber is modified to have a conventional graded index profile to suppress unwanted modes propagating along the guide.

Abstract: An exposure meter provides a display indicating the brightness of selected portions of a scene to be photographed. In one embodiment, a photometering block including a plurality of light sensitive elements is employed, and there is an automatic fixed display indicating the brightness level of the brightest and the darkest portions of the objective scene together with a display of a median value. Another embodiment employs a spot photometering device with only one light sensitive element, and a display of the brightness level of different portions of the scene selected by the photographer.

Abstract: A hermaphroditic connector for coupling a pair of single optical fibers is disclosed. The connector comprises a pair of connector members each containing at least one single optical fiber terminated by a termination pin. The pin includes a metal eyelet crimped about the optical fiber in three places providing three, spaced, curved indentations which centrally position the fiber in the pin. When the connector members are mated, the mating termination pins are positioned so that the indentations therein are generally aligned. A cam or spring device is forced into the indentations in the mating termination pins to accurately laterally align the pins and, hence, the optical fibers therein.

Abstract: A fiber optic T-coupler comprised of solid primary and branch cores adapted to transmit light therethrough. The primary core is provided with a recess cooperating with the branch core, typically arranged at a right-angle with the primary core, to define a reflective surface whose surface area forms a ratio with the cross-sectional surface area of the primary core, which ratio corresponds to that between the light deflected by the reflective means into the branch core relative to the total light entering the primary core prior to deflection.The reflective surface may be provided within the body of either the primary core or the branch core and plural reflective surfaces may be provided for handling bi-directional transmission or reception or for separating the transmission and reception of light.

Abstract: In a disconnectable low-loss optical connector for optical fiber light guides, the fiber is precisely located in the body of the connector form in a molding die cavity. The portion of the cavity that forms the mating surface of the molded connector body corresponds to a frustum of a cone whose axis is a reference point for determining the exact location of the fiber. The fiber is placed in a sleeve-like member to form a subassembly around which the connector body is molded. One end of the member has a port located in the tip of the frustum of the molding cavity and aids in the precise formation of the mating surface. When the molding cavity is filled to form the molded connector body, gas pockets which form and produce voids in the molding material are accepted in a flow of filler material and prevented from interfering with the formation of the mating surface. The fiber which protrudes out of the tip of the mating surface is then cut and polished to form the junction end.

Abstract: A scanning radiometer in which at least one curved mirror is integral with a drivable optical system. Thermal radiation is directed onto a detector facing the mirror at a distance. An electronic system performs a weighting evaluation corresponding to the position of the detectors, and a threshold value is indicative of the degree of radiation of the observed object shown on a display unit. The optical system together with the detectors is located about axes containing the center of curvature of the curved mirror and is rotatable in steps or continuously. The mirror is, furthermore, shaped in the form of a hollow sphere or a hollow sphere segment. The latter avoids irradiation of detectors by scatter radiation incident via the aperture with boundaries running parallel to the optical axis or with a boundary expanding funnel-like from the entry window towards the mirror.

Abstract: An improved and simplified connector scheme is disclosed for coupling the light output of a light emitting diode mounted in a flexible circuit to an optical fiber. The LED is mounted in flexible circuitry by a technique known as "poke in" which comprises forming a substantially H-shaped slot in a conductor portion of a circuit and the underlying flexible substrate on which the circuit is formed and inserting an LED into the slot in edgewise fashion. The optical fiber is placed in abutting position against one side edge of the LED and a suitable potting agent is applied thereto to make an integral unit. Preferably the potting agent also includes an outer layer of light reflecting material to prevent unwarranted loss of light from the remaining sides of the LED.

Abstract: The invention provides a method and apparatus for measuring and recording the amount of solar energy falling at a place over a given period of time, comprising means for producing a frequency signal representative of the energy falling at the place, the provision of the frequency signal being controlled in response to the level of solar energy falling exceeding a morning threshold and falling below an evening threshold, and the frequency signal being applied to a counter, preferably fitted with print-out means, whereby the counter may record the total energy falling between the morning and evening thresholds.

Abstract: Fiber optic connector apparatus and methods and apparatus for applying the fiber optic connector apparatus to the fiber optic cable is provided in accordance with the teachings of the instant invention. The fiber optic connector apparatus includes a metallic nose piece having a first apertured end portion for butting optical fibers exposed at the aperture and a second apertured end portion for receiving the fiber optic cable. An application device for holding the nose piece in alignment with cable to be attached is provided to heat the nose piece to a temperature to cause protective sheathing on the cable to flow. Upon melting, an end portion of the cable to be attached is biased against the second apertured end portion to cause it to be displaced into the nose piece as the protective sheathing begins to flow to expose optical fibers at the first end portion and, upon cooling, maintain the portion of the cable within the nose piece in a compressed, adhered condition.

Abstract: The present invention relates to an integrated circuit body suited to be applied for a TTL single reflex camera, by arranging at least two of the three circuit parts, namely the indication circuit part presenting an indication function, the light sensing circuit part presenting a light sensing function and the control-operation circuit part.

Abstract: An optical fiber cable comprising a close-packed assembly of cylindrical strength members defining at least one cuspid interstice loosely receiving a single optical fiber therein.

Abstract: A photometer for providing a measurement of shutter speed or aperture setting corresponding to a preselected value of the other comprises a photodiode supplying a voltage proportional to the logarithm of the measured light intensity. This voltage controls the frequency of an oscillator supplying pulses to a counting circuit during a time interval set by a timer.

Abstract: A mounting arrangement for a surface-acting solid state device (e.g. a PIN diode, an avalanche diode or an LED) and for coupling the device to an optical fiber transmission line. The arrangement includes a housing for the device header and the end of a jewelled ferrule containing a length of a first optical fiber transmission line. One end of the first transmission line projects from the ferrule and is aligned with the device. The other end of the ferrule mates with a ferrule ended second optical fiber transmission line.

Abstract: An optical fiber connector in which each mating fiber is provided with a termination in the form of a cast metal sleeve fitted in a metal ferrule.

Abstract: Binary information developed on a rotating member is applied in the form of light signals to one end of an optical fiber which is disposed about the rotating member and positioned adjacent a stationary light detector. The surface of the optical fiber is roughened so that a portion of the light that axially propagates along the optical fiber is transmitted through the roughened wall of the fiber and is received at the light detector. The latter converts the thus received light signals into corresponding binary signals. In accordance with one aspect of the present invention, plural independent data coupling channels may be employed.

Abstract: An optical fiber tap is described which comprises a beamsplitter formed by positioning bevelled, parallel endfaces of two segments of optical fiber in coaxial alignment and in close proximity to each other. A suitable dielectric film, such as air, fills the gap between the endfaces. Light propagating into the tap from the first fiber segment is partially reflected and partially refracted at the bevelled endfaces. The refracted portion enters the second fiber segment and the reflected portion leaves the tap and is detected by a photodetector. By choice of the proper angle for the bevelled endfaces, the tap can be made substantially mode independent. A greater degree of mode independence can be obtained by interposing a steady-state mode exciter between the light source and the beamsplitter.

Abstract: A single-mode optical fiber to a single-mode optical channel waveguide end-fire coupler. A single fiber held within a capillary tube and positioned by a micropositioner is adjusted for greatest light output and then secured by an epoxy to one end of a channel waveguide. The two elements are then secured in place in a slot in the capillary tube which prevents rotation of the waveguide relative to the single fiber.

Abstract: An input/output coupler for multi-mode optical or light conducting fibers comprises a substrate, a first light conductor, which is disposed on the substrate and has an end face forming a coupling point or surface, a main light conducting fiber, which is disposed on the substrate with an end face at the coupling surface and a center of the end face offset by a distance a from the center of the coupling surface, and a strip waveguide, which is coupled to a branch light conducting fiber and is disposed on the substrate with an end face in contact with a portion of the coupling surface so that a portion of a light signal entering the coupler in the first light conductor is applied to both the main and branch light conducting fibers and signals entering the coupler in the branch and main light conducting fibers are applied to the first light conductor. The first light conductor may be either a light conducting fiber or an additional strip waveguide, which is coupled to a light conducting fiber.

Abstract: A connector means for connecting together two optical fibers whose ends have been stripped of optical cladding to expose the cores. The connector comprises means for gripping the fibers at unstripped sections thereof with a predetermined length of fiber extending from datum or reference surfaces on the connector such that the ends of the stripped fibers face each other and are spaced apart a very short distance of the order of not more than one and one-half times the core diameter. The connector further comprises a pair of elastomeric elements each with grooves of semi-cylindrical cross-section formed therein that fit together to form a cylindrical bore which retains the stripped ends of the two fibers. Because the diameter of the cylindrical bore is less than the diameter of either core retained therein, the resilient walls of the cylindrical bore will give way and will thereby force the ends of the two cores into substantial concentric alignment.

Abstract: A system and apparatus for providing a measure of ESI (equivalent sphere illumination) as a function of Lb (background luminance) and Lt (task luminance) and in which a pair of envelopes are provided each having a varying transmittance such that one envelope can provide an indication of the term (Lb-Lt) and the other an indication of Lb whereby ESI can be determined.