Electrode arrangement for lensing method

• US 4,804,395 A
• Filed: 01/13/1987
• Issued: 02/14/1989
• Est. Priority Date: 01/13/1987
• Status: Expired due to Fees

• Current Assignee: ITT Corporation (ITT, Inc.)
• Original Assignee: ITT Corporation (ITT, Inc.)
• Inventors: Clark, Kenneth M., Coutts, Bruce
• Primary Examiner(s): LINDSAY JR, ROBERT
• Application Number:
  US07/002,883
• Time in Patent Office: 763 Days
• Field of Search: 65/2, 65/10.2, 65/11.1, 65/37, 65/40, 65/36, 264/96.18, 219/122, 219/121 EB, 219/121 EF, 219/121 EG, 219/121 ER, 219/121 ES, 219/121 ET, 219/121 EX, 373/2, 373/3, 373/4, 373/22, 373/23, 373/24
• US Class Current: 65/387
• 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
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262

Abstract

A system is provided for positioning a pair of electrodes on either side of the end portion of an optical fiber extending through a contact, to establish an arc through a cross-aperture in the contact and across the fiber to melt the fiber into a lens, which assures close control of the arc and which prolongs the life of the electrodes. The tips of the electrodes are positioned to lie slightly within opposite ends of the cross-aperture, to avoid establishing an arc between the electrodes which passes around the contact instead of through the cross-aperture. The electrodes are spaced apart by at least about eight times the diameter of the optic fiber, to avoid deposition of vapors from the heated optic fiber onto the electrodes. The cross-aperture extends to the tip of the contact, so the contact can be moved along its axis to a position where the electrodes lie on opposite sides of the fiber end portion.

Claims

1. A method for forming a lens at the end of an optical fiber comprising:

positioning an optical fiber between the tips of a pair of electrodes, and establishing an electric arc which includes a visible arc portion between the electrode tips, at an arc current and duration which melts the fiber to form it into a lens of greater diameter than the fiber;

said step of positioning including projecting said fiber through a longitudinal hole in an elongated contact, wherein the longitudinal hole extends along the length of the contact, until the tip of the fiber has passed at least partially through a cross-aperture in the contact which extends between opposite sides of the contact and largely perpendicular to said longitudinal hole;

said step of positioning including positioning the tips of said electrodes so they lie within opposite sides of said cross-aperture, with the spacing between the electrode tips being less than the width of said contact along said cross-aperture but at least about eight times the fiber diameter.