Variable ratio optical junction device

• US 4,135,779 A
• Filed: 08/02/1976
• Issued: 01/23/1979
• Est. Priority Date: 08/02/1976
• Status: Expired due to Term

• Current Assignee: Corning Glass Works Inc. (Corning Incorporated)
• Original Assignee: Corning Glass Works (Corning Incorporated)
• Inventors: Hudson, Marshall C.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Hille, Rolf
• Application Number:
  US05/711,104
• Time in Patent Office: 904 Days
• Field of Search: 350/96 C
• US Class Current: 385/45
• CPC Class Codes: G02B 6/2804 forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers

Abstract

An optical fiber junction device for coupling a pair of optical fibers with a third optical fiber. A portion of the cladding is etched from the end portions of the pair of fibers, and those end portions are then secured together in side-by-side relationship so that their endfaces are coplanar. The third fiber is so disposed that the end portion thereof is substantially parallel to the end portions of the pair of fibers, and its endface is adjacent to the endfaces of the pair of fibers. Means is provided for causing lateral movement between the endfaces of the pair of fibers and that of the third fiber to vary the amount of light coupled between the pair of fibers and the third fiber.

Claims

1. An optical junction device comprising first, second and third optical fibers,

each comprising a core of transparent material surrounded by a layer of transparent cladding material having a refractive index lower than that of said core material, the end portions of said first and second fibers being fused together in side-by-side relationship, said end portions of said first and second fibers being fused together to such an extent as to form a single composite fiber having two cores therein, the cladding layers of said first and second fibers combining to form a single cladding layer of elliptical cross section,

the endfaces of said first and second fibers being substantially coplanar and being substantially perpendicular to the fiber axes,

means for supporting the end portion of said third optical fiber so that its axis is substantially parallel with the axes of said first and second fibers and its endface is substantially perpendicular to the axis thereof and is disposed against the endfaces of said first and second fibers, and

means for causing relative movement between the endfaces of said first and second fibers and said third fiber, said movement causing the center of said third fiber to traverse a line passing through the centers of the endfaces of said first and second fibers.

2. A device in accordance with claim 1 wherein at least a portion of the cladding layer is etched from the end portions of said first and second fibers.

3. A device in accordance with claim 2 wherein the etched end portions of said first and second fibers are immersed in index matching fluid having a refractive index lower than that of the cores of said fibers.