Method of forming a fiber optic coupler by dynamically adjusting pulling speed

• US 5,931,983 A
• Filed: 08/05/1997
• Issued: 08/03/1999
• Est. Priority Date: 09/24/1996
• Status: Expired due to Fees

• Current Assignee: Cary Bloom
• Original Assignee: Cary Bloom
• Inventors: Bloom, Cary
• Primary Examiner(s): HOFFMANN, JOHN M
• Application Number:
  US08/906,084
• Time in Patent Office: 728 Days
• Field of Search: 65/411, 65/381, 65/378
• US Class Current: 65/378
• 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 6/2835 formed or shaped by thermal treatment, e.g. couplers

Abstract

Fused biconical tapered couplers formed from the pulling of heated optical fibers have controllable coupling ratios by dynamically adjusting the heat intensity and pull speed during fabrication. Fiber coupler fabrication begins by arranging two optical fibers, heating the optical fibers using a heat source a predetermined distance from the optical fibers, and pulling the optical fibers at an initial pulling velocity as the heated optical fibers soften. The heat source is moved away from the optical fibers and the pulling velocity is selectively reduced in response to a substantial change in the detected coupling ratio. Changes in the coupling ratio are controlled by selectively reducing the pulling speed and the heat intensity to a point where the pulling of the optical fibers may be halted, and the heat removed, without a substantial change in the detected coupling ratio. The coupling ratio may be monitored at different wavelengths for fabrication of wideband couplers and wavelength division multiplexers.

Claims

1. A method of forming a fiber optic device from first and second optical fibers contacting each other at a region, comprising the sequential or non-sequential steps of:

providing incident heat on the first and second optical fibers at the region;

pulling the heated first and second optical fibers at a first velocity at a variable tension;

monitoring a change of a coupling ratio between the first and second optical fibers;

dynamically adjusting the first velocity when the change in the coupling ratio is detected between the first and second optical fibers; and

selectively repeating said adjusting step when the change in the coupling ratio is detected.

2. A method of forming a fiber optic device from first and second optical fibers contacting each other at a region, comprising the sequential or non-sequential steps of:

providing incident heat on the first and second optical fibers at the region;

pulling the heated first and second optical fibers at a velocity under a variable tension;

monitoring a change of a coupling ratio between the first and second optical fibers, the change in the coupling ratio varying between an initial coupling ratio and a desired coupling ratio;

dynamically adjusting the velocity when the change in the coupling ratio is detected between the first and second optical fibers at any coupling ratio value between the initial coupling ratio to the desired coupling ratio; and

dynamically and selectively repeating said adjusting step when the change in the coupling ratio is detected at any coupling ratio value between the initial coupling ratio to the desired coupling ratio.

3. A method according to claim 2, wherein the change in coupling ratio comprises at least a substantial change in the coupling ratio.