Optical fiber having an aspherical lens thereon and method of making same

• US 5,037,174 A
• Filed: 01/31/1990
• Issued: 08/06/1991
• Est. Priority Date: 01/31/1990
• Status: Expired due to Term

• Current Assignee: Avago Technologies Fiber IP Singapore PTE Limited (Broadcom, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Thompson, David R.
• Primary Examiner(s): Healy, Brian
• Application Number:
  US07/472,995
• Time in Patent Office: 552 Days
• Field of Search: 350/96.15, 350/96.17, 350/96.18, 350/96.20, 350/96.29, 350/320, 65/2, 65/10.2, 65/12, 65/37, 65/39
• US Class Current: 385/33
• CPC Class Codes: G02B 6/2551 using thermal methods, e.g. fusion welding by arc discharge, laser beam, plasma torch
• CPC Class Codes: G02B 6/2552 reshaping or reforming of light guides for coupling using thermal heating, e.g. tapering, forming of a lens on light guide ends
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements

Abstract

An optical fiber having an axis therethrough and having a tip thereon comprising a first tapered region and a second adjacent tapered region. The second tapered region terminates in an aspherical lens. Each of the tapered regions having a surface thereon. The surface of the first tapered region defines an angle with respect to the axis of the fiber that lies in the range from about ten (10) to about thirty (30) degrees, while the surface of the second tapered region defining an angle with respect to the axis of the fiber that lies in the range from about thirty-five (35) to about sixty (60) degrees. The second tapered region is produced as a result of a jerking action imposed during the drawing of the fiber.

Claims

1. An optical fiber having an axis and having a tip thereon, the tip comprising a first tapered region and a second adjacent tapered region, the second tapered region terminating in an aspherical lens, each of the tapered regions having a surface thereon, the surface of the first tapered region defining an angle with respect to the axis of the fiber that lies in the range from about ten (10) to about thirty (30) degrees, the surface of the second tapered region defining an angle with respect to the axis of the fiber that lies in the range from about thirty-five (35) to about sixty (60).

2. The fiber of claim 1 wherein the angle defined by the first tapered region is about eighteen (18) degrees.

3. The fiber of claim 2 wherein the angle defined by the second tapered region is about forty-five (45) degrees.

4. The fiber of claim 1 wherein the angle defined by the second tapered region is about forty-five (45) degrees.

5. The fiber of claim 4 wherein the aspherical lens is substantially hyperbolic in section.

6. The fiber of claim 3 wherein the aspherical lens is substantially hyperbolic in section.

7. The fiber of claim 2 wherein the aspherical lens is substantially hyperbolic in section.

8. The fiber of claim 1 wherein the aspherical lens is substantially hyperbolic in section.

9. A method of forming a tip on an optical fiber comprising the steps of:

(a) positively clamping a length of an optical fiber at first and second spaced clamping points,

(b) directing an energy arc at a predetermined separation point on the fiber intermediate the first and second clamping points to define with respect to the separation point a first and a second portion on the fiber,

(c) relatively moving at least one of the clamps with respect to the other at a first predetermined separation acceleration in the presence of the energy arc thereby to define a first tapered region on at least one portion of the fiber,

(d) stepwise increasing the separation acceleration to jerk apart the fiber and separate the first and second portions and to form a nipple-like extension on at least the portion of the fiber having the first tapered region,

(e) cooling the portion having the nipple-like extension thereon below its transition temperature, and

(f) thereafter introducing the nipple-like extension into the arc to form the nipple-like extension into a second tapered region having an aspherical lensed end.

10. The product produced by the process of claim 9.