Fiber optic cable termination

• US 4,738,505 A
• Filed: 12/04/1986
• Issued: 04/19/1988
• Est. Priority Date: 12/04/1986
• Status: Expired due to Term

• Current Assignee: RCA Corporation
• Original Assignee: RCA Corporate
• Inventors: Jones, Theodore L.
• Primary Examiner(s): Lee, John
• Assistant Examiner(s): Ngo, John
• Application Number:
  US06/938,146
• Time in Patent Office: 502 Days
• Field of Search: 350/96.20, 350/96.21, 350/96.22, 350/96.23, 350/320, 156/85, 156/86, 156/293
• US Class Current: 385/86
• CPC Class Codes: G02B 6/4248 Feed-through connections for the hermetical passage of fibres through a package wall see provisionally also G02B6/4428

Abstract

A method is disclosed for making a termination between (a) a fiber optic cable having an optical fiber, a plurality of reinforcement strands positioned about the optical fiber, and a jacket positioned about the reinforcement strands; with (b) an electro-optic component housing having a tubular extension. In accordance with the method of this invention, in the initial step, a predetermined length of the outer jacket is removed from the fiber optic cable to expose a length of optical fiber and reinforcement strands. A rigid sleeve is then slideably placed onto the optical fiber until it extends a distance under the jacket and is retained thereby. The optical fiber is then hermetically sealed to the sleeve, suitably by solder introduced through one or more holes in the wall of the sleeve. The seal and the integrity of the fiber can be tested at this point, a decided advantage. The rigid sleeve is inserted into and through the tubular extension and sealed therein so that the optical fiber may be coupled to a device within the housing. A layer of adhesive is applied to the tubular extension and the exposed portion of the rigid sleeve. The reinforcement strands are positioned about the outer diameter surface of the tubular extension and a layer of protective material is bonded thereover. A preferred protective material is heat-shrink tubing.

Claims

1. A method for forming a termination of a fiber optic cable with an electro-optic component housing wherein

the fiber optic cable is comprised of an optical fiber, a plurality of reinforcement strands aligned about the length of the optical fiber, and a jacket positioned about the reinforcement strands, and

the electro-optic component housing has an interior compartment, a tubular extension of a predetermined length with a passage in communication with the interior compartment, and an outer diameter surface, said method comprising the steps of:

(a) removing a terminal portion of the jacket which is at least as long as the predetermined length of the tubular extension, thereby exposing a length of optical fiber and lengths of reinforcement strands at one end of the jacket on the fiber optic cable;

(b) slideably inserting a rigid sleeve over the optical fiber and under the reinforcement strands for a distance such that the sleeve extends under the jacket and is retained thereby, said rigid sleeve being at least as long as the distance it extends under the jacket plus the predetermined length of the tubular extension and having at least one opening in the wall thereof at the end opposite to the jacket;

(c) hermetically sealing the optical fiber into the rigid sleeve;

(d) inserting the exposed length of the rigid sleeve into and through the passage to the interior compartment of the component housing;

(e) bonding said sleeve to the tubular extension;

(f) providing a layer of adhesive over the tubular extension, and the exposed portion of the rigid sleeve;

(g) positioning the exposed reinforcement strands about the outer diameter surface of the tubular extension; and

(h) providing a layer of protective material over the exposed reinforcement strands and an end portion of the jacket.

2. A method in accordance with claim 1, wherein the optical fiber is sealed into the rigid sleeve by introducing solder into the sleeve through said opening.

3. A method in accordance with claim 1, wherein the layer of adhesive is adhesive tubing.

4. A method in accordance with claim 1, wherein the reinforcement strands are positioned about the outer diameter surface of the tubular extension and the adhesive is applied thereover.

5. A method in accordance with claim 4, wherein the exposed lengths of reinforcement strands are divided into at least two groups of about equal size which are spaced at about equal distances on the outer diameter surface of the tubular extension.

6. A method in accordance with claim 1, wherein the layer of protective material is heat-shrink tubing.

7. A method in accordance with claim 6, wherein the layer of adhesive is provided on the inside surface of the heat-shrink tubing and steps (f) and (h) are carried out simultaneously after step (g).

8. A method in accordance with claim 1, additionally including the steps of testing the optical fiber after it has been sealed into the sleeve to determine if it is hermetically sealed and the fiber is intact prior to inserting the sleeve into the tubular extension.

9. A termination of a fiber optic cable with an electro-optic component housing wherein

the fiber optic cable includes an optical fiber and a plurality of reinforcement strands aligned about the length of the optical fiber and a jacket positioned about the reinforcement strands except at a terminal end wherein a portion of the jacket of at least a predetermined length is removed to provide an unjacketed length of the optical fiber and unjacketed lengths of reinforcement strands;

and

the electro-optic component housing has an interior compartment and a tubular extension of said predetermined length having an internal passage in communication with the interior of the component housing and an outer diameter surface, said termination being comprised of the unjacketed length of fiber hermetically sealed within a length of rigid sleeve which is positioned within the tubular extension and extends from at least the interior compartment of the component housing to a point a predetermined distance within the jacket and underlying said reinforcement strands, the unjacketed reinforcement strands being positioned about the outer diameter of the tubular extension and bonded thereto by a layer of adhesive and a layer of protective material overlying and bonded to the tubular extension and a portion of the jacket of the fiber optic cable.

10. A termination in accordance with claim 9, wherein the layer of protective material is a length of shrink-fit tubing which is in shrink-fit and adhesive engagement with the reinforcement strands and the jacket.

11. A termination in accordance with claim 9, wherein the layer of adhesive is a length of adhesive tubing.