American Optical Corporation

Eotec

3M Innovative Properties Company

Exxon Research and Engineering Company

3M Fiber Optic Products, Inc.

David A Krohn

Emil W Deeg

Robert E Graf

Edmond I Vinarub

David R Maack

John R Ellison, Jr

Trevor Wayne MacDougall

Paul Eric Sanders

Elias Snitzer

Walter P Siegmund

Bernard Grolman

James Craig Novack

Bryon J Cronk

Mokhtar S Maklad

Peter E Raber

James W Laumer

Seymour Merrin

Tracy R Woodward

Louis A Buffone

An optical fiber element includes an optical fiber having a numerical aperture ranging from 0.08 to 0.34 and a protective coating affixed to the outer surface of the optical fiber. The protective coating has a Shore D hardnees value of 65 or more and remains on the optical fiber during connectorization so that the fiber is neither damaged by the blades of a stripping tool nor subjected to chemical or physical attack.

Optical fiber element having a permanent protective coating with a Shore

A method of producing a hollow core optical fiber comprises the steps of depositing a thermal buffer layer on the interior wall of a silica tube, depositing a film of germanium silicate cladding on said buffer layer, heating the composite structure so formed to its drawing temperature, and drawing the heated composite structure to form a hollow core optical fiber.

Low loss infrared transmitting hollow core optical fiber method of

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.

Fiber optic displacement measuring apparatus

An apparatus for determining the rotational position of a shaft comprises opposed first and second disks mounted for relative rotation about a predefined axis, with one of the disks being mounted to the shaft for rotation therewith and the other of the disks being maintained in a reference position. First and second rows of spaced apertures are provided on each disk, which lie in concentric paths of different radial distance from the predefined axis, the first rows being at the same radial distance from the axis and second rows being at the same radial distance from the axis. These apertures are positioned so that apertures of the first rows move into alignment while apertures of the second rows move out of alignment as the disks are rotated relative to each other. A first beam of light of predetermined intensity is oriented so as to intersect the paths of the first rows of apertures, and a second beam of light of predetermined intensity is oriented so as to intersect the paths of the second rows of apertures. First and second photosensors are aligned respectively with the first and second beams of light, and the photosensors are positioned so that the disks are in front of the respective photosensor for each light beam. Each photosensor provides an electric output signal relative to the intensity of light sensed by it and the two output signals are differentially processed to provide an orientation signal representative of the relative rotational position of the disks.

Precision optoelectronic rotational position sensor

An apparatus is disclosed for sensing rotational or angular position of a shaft. The apparatus incorporates two light transmission paths, each having a separate photodetector providing an electrical signal in response to the intensity of received light. The electrical signals from the photodetectors are differentially processed to obtain a signal representative of rotational position. Devices are provided in each of the light transmission paths to vary the intensity of light transmitted in the path, and these devices are mechanically coupled to the shaft so that the variations in the respective light paths are opposite. The differentially processed photodetector signals are therefore unaffected by the absolute position of the shaft but are responsive only to deviations from a reference position. Furthermore, this differentially processed signal exhibits a higher degree of linearity was heretofore obtainable. Various embodiments are disclosed for achieving this opposite variation in the respective light paths. Preferably, the angular position sensor is utilized in a torque wrench or similar device for sensing applied torque.

Optoelectronic rotational position sensor

An apparatus is disclosed for sensing rotational or angular position of a shaft. The apparatus incorporates two light transmission paths, each having a separate photodetector providing an electrical signal in response to the intensity of received light. The electrical signals from the photodetectors are differentially processed to obtain a signal representative of rotational position. Devices are provided in each of the light transmission paths to vary the intensity of light transmitted in the path, and these devices are mechanically coupled to the shaft so that the variations in the respective light paths are opposite. The differentially processed photodetector signals are therefore unaffected by the absolute position of the shaft but are responsive only to deviations from a reference position. Futhermore, this differentially processed signal exhibits a higher degree of linearity was heretofor obtainable. Various embodiments are disclosed for achieving this opposite variation in the respective light paths. Preferably, the angular position sensor is utilized in a torque wrench or similar device for sensing applied torque.

A sensor element for a liquid level sensor of the 'light prism' type is constructed so as to have a gradually tapering frusto-conical shape and a sensing surface at its lower tip. Such a shape has a tendency to collomate the light transmitted within it and to concentrate all critical reflections in the lower tip of the sensor element, thereby defining a relatively concentrated sensing area. At the same time, the sensor element is shaped and dimensioned in the vicinity of the sensing surface so that the surface tension of the droplet causes the droplet to be lifted upwardly and away from the sensing surface. Any deliterious effect of the droplet on the sensing ability of the sensor is thereby avoided.

Liquid level sensor

A utility meter has a plurality of rotating shafts which have angular positions corresponding to the digits of a consumption reading. A cam is attached to that shaft which is associated with the least significant digit. The cam has a light reflecting track. Light from a light source is reflected off the track to a photodetector along an optical path which varies in length in accordance with angular cam position. Electronic circuitry is connected to the light source and photodetector and produces an output signal in digital form which has a frequency related to intensity of light incident upon the photodetector.

Method and components for remote reading of utility meters

A method is provided for making an optical fiber by melting and cladding a multi-component core glass without adding the contamination that is normally associated with these processes. As an initial step, a pure multi-component glass is melted in a high purity silica crucible. The temperature of the glass in the crucible and the temperature of the orifice thereof are controlled so that a cane of glass is drawn from the bottom of the crucible. This cane of glass is fed into a silica or borosilicate tube which is being drawn into a fiber. This results in an optical fiber in which the multi-component glass forms the core while the tube forms the cladding.

Low loss optical fibers

A process is disclosed for manufacturing an optical fiber comprising a silica cladding and multi-component glass core wherein a tube made of the cladding material serves as a crucible in which the core glass is melted and fined. The core glass includes silicon dioxide, boron oxide, barium oxide or lead oxide (or a combination of both, and an alkali oxide). The materials are selected to provide a high numerical aperture, rapid melting and stability at the high temperatures required to draw the fiber. In accordance with a further feature of the invention, the batch material for the core is actually melted as it is falling to the bottom of the silica tube, thereby increasing the speed of melting and further facilitating outgassing of effluents.

Method of manufacture of optical fiber

A process is disclosed for making an optical fiber having a graded index glass core enveloped by a cladding material. The ingredients from which the core glass is to be formed are dropped into a closed tube of the cladding material which is more refractory than the core glass. The ingredients are melted to form a glassy liquid which is fined within the tube. Fining takes place at a temperature sufficiently high to cause a relatively fast reaction between the core glass and cladding, resulting in a partial mixing of the cladding and core glasses. The mixed glasses have an index of refraction intermediate that of the core and cladding at the interface. The temperature is then elevated further and the tube and glassy liquid drawn into a fiber.

Method of manufacturing graded index optical fibers

A sealing glass composition having a thermal coefficient of expansion (from room temperature to 300.degree. C.) of about 90.times.10 -7/.degree.C. and a softening temperature of about 406.degree. C. is provided and consists essentially of the following ingredients in the following proportions: PbO, 66%; B.sub.2 O.sub.3, 18%; ZnO, 15%; and Fining Agent, 1%.

Sealing glass

A process is disclosed for making an optical fiber having a graded index glass core enveloped by a cladding material. The ingredients from which the peripheral part of the core glass is to be formed are placed in a closed tube of the cladding material which is more refractory than the core glass. The ingredients are melted to form a glassy liquid which is fined within the tube and then coated (for example, by rotational casting) on the inner surface of the tube. Additional ingredients, from which the inner part of the core glass is to be formed, are then placed in the coated tube, melted and similarly coated on the inner surface of the tube. In this way successive core glass layers, each having a different index of refraction, may be formed within the tube of cladding material. The temperature is then elevated further and the tube and glassy liquid drawn into a fiber.

Glass lenses or lens blanks, containing all the ingredients necessary to produce phototropic or photochromic behavior, are treated in a conventional production furnace to produce a locally variable heat treatment, wherein at least one portion thereof is raised to a temperature exceeding the glass strain point but not the softening point, and other portions are heated to variable temperatures decreasing from the strain point. The treatment causes development of phototropic or photochromic behavior only in those portions of the lenses or lens blanks exposed to the temperature above the strain point.

Preparation of photochromic gradient lenses

The invention achieves local variation, or a continuous gradation, in photochromic or phototropic properties across the face of glass lenses and lens blanks, especially those of ophthalmic quality. The lenses and lens blanks contain all those ingredients required to produce photochromic or phototropic behavior. They are exposed to a locally variable temperature field or environment, in such manner as to, in at least one portion of the lens or lens blank cause the temperature therein to exceed the strain point but not the softening point of the glass. In other portions of the lens or lens blank the temperature is below the strain point, thus causing development of phototropic or photochromic behavior only in those portions of the lens or lens blank exposed to the temperatures above the strain point.

Growing community of inventors

Hamden, CT, United States of America

David A Krohn