Patents by Inventor Alexander W. Lightstone

Alexander W. Lightstone has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4712862
    Abstract: Fiber optic connectors typically have a light reflection occurring at the fiber to air interface. This reflection may be minimized by a connector having a supporting means with an opening therethrough, a pellicle and having first and second major surfaces wherein the first major surface is attached to the supporting means and extends over the opening and a low refection coating on the second major surface. The connector may be assembled by supporting the fiber and positioning the pellicle such that the end face of the fiber is adjacent the first major surface. The connector may also be assembled by forming the supporting means, forming the pellicle and attaching the pellicle to the supporting means such that the pellicle extends over the opening.
    Type: Grant
    Filed: August 27, 1986
    Date of Patent: December 15, 1987
    Assignee: RCA Corporation
    Inventor: Alexander W. Lightstone
  • Patent number: 4654678
    Abstract: The invention is an improved avalanche photodiode having reduced electrical noise arising from spurious surface generation of charge carriers. The avalanche photodiode includes active and neighboring regions adjacent a first surface of a semiconductor body with a gap region therebetween and a channel extending a distance into the semiconductor body from a portion of the second opposed surface opposite the gap region. A P-N junction is formed between regions of opposite conductivity type including a portion thereof over the channel. Since the dopant concentration at the junction is less over the channel, the local avalanche gain over the channel is less, thereby reducing the noise contribution from carriers generated in the gap region.
    Type: Grant
    Filed: August 30, 1985
    Date of Patent: March 31, 1987
    Assignee: RCA, Inc.
    Inventors: Alexander W. Lightstone, Paul P. Webb, Robert J. McIntyre
  • Patent number: 4637126
    Abstract: An avalanche photodiode includes a region of second conductivity type extending a distance into a substrate and a region of first conductivity type extending a further distance into the substrate of first conductivity type with a P-N junction therebetween. The invention is a method for fabricating an avalanche photodiode having a specified breakdown voltage. The method includes the step of measuring the concentration of the first type conductivity modifiers and removing a portion of the surface of the substrate prior to forming the region of second conductivity type. This method provides control of the concentration of the first type conductivity modifiers at the P-N junction and thereby controls the breakdown voltage.
    Type: Grant
    Filed: August 30, 1985
    Date of Patent: January 20, 1987
    Assignee: RCA, Inc.
    Inventor: Alexander W. Lightstone
  • Patent number: 4449781
    Abstract: An optical fiber coupler is described for operatively coupling together two or more optical fibers. Each coupler consists of several biconically tapered fibers. The biconical sections of each fiber are placed side by side or twisted around one another, and fused together. The couplers are typically made of optical fibers having a diameter in the range from about 100 to about 300 microns. The fiber comprises a core of glass having a high index of refraction and cladding of glass with a low index of refraction. The cladding of each biconical section has been reduced by chemical etching, plasma etching, ion-milling, abrasion or the like, to a thickness not exceeding 25 percent of the core diameter, more preferably less than 10 percent and most preferably from about 5 percent to about 10 percent of the core diameter. The couplers are of step or graded index optical fiber. The design can be adapted as multiport access couplers when more than two fibers are involved.
    Type: Grant
    Filed: November 20, 1981
    Date of Patent: May 22, 1984
    Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of National Defense
    Inventors: Alexander W. Lightstone, H. Keith Eastwood, Frank Szarka
  • Patent number: 4439221
    Abstract: An apparatus and method are described for making an optical fiber coupler. A pair of optical fibers are supported in predetermined orientation by positioning means. The latter are spaced apart along a common axis. The optical fibers are positioned within tube means of a selected size intermediate the positioning means. In use, the tube means functions as a furnace to distribute heat uniformly to at least a portion of the fibers to fuse the same together. One of the positioning means preferable is rotatable, to enable twisting of the fibers. It is also preferable that at least one fiber has a tensile force applied to it. More preferably, the tensile force is sufficient to cause necking of the heated fiber, thereby forming a biconical section therein. Rotation of one positioning means through about one half revolution normally causes twisting of the biconical section and fusion thereof to the other fiber. Typically, both fibers are subject to a pulling force to create biconical sections.
    Type: Grant
    Filed: January 14, 1983
    Date of Patent: March 27, 1984
    Assignee: Her Majesty the Queen in right of Canada as represented by the Minister of National Defence
    Inventors: Lawrence C. Smyth, Alexander W. Lightstone