Browse Prior Art Database

Fiber-Optic Cable Adaptable to Fault Isolation

IP.com Disclosure Number: IPCOM000042651D
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Balliet, L: AUTHOR [+3]

Abstract

A fiber-optic cable construction is described that makes it possible to precisely locate a break in the cable and subsequently make repairs. Because of mishandling or accident, glass fibers in a fiber-optic cable are occasionally broken. If the break can be precisely located, repairs are easily made by splicing techniques already developed in the art. Optical time domain reflectometers (OTDRs) are commonly used to locate a break. However, these instruments are precise to only a few meters and only provide the distance relative to the end termination. In most cable installations, a lack of exact routing information also adds several meters to precisely locating a fault. Consequently, unless a great amount of slack cable is available near the break, the ability to make a repair depends on good fortune or physical evidence.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 2

Fiber-Optic Cable Adaptable to Fault Isolation

A fiber-optic cable construction is described that makes it possible to precisely locate a break in the cable and subsequently make repairs. Because of mishandling or accident, glass fibers in a fiber-optic cable are occasionally broken. If the break can be precisely located, repairs are easily made by splicing techniques already developed in the art. Optical time domain reflectometers (OTDRs) are commonly used to locate a break. However, these instruments are precise to only a few meters and only provide the distance relative to the end termination. In most cable installations, a lack of exact routing information also adds several meters to precisely locating a fault. Consequently, unless a great amount of slack cable is available near the break, the ability to make a repair depends on good fortune or physical evidence. The cable design described here permits direct observation of the fiber and eliminates difficulties of the nature described. Most fiber-optic transmission employs light in the near-infrared region, 850- or 1300-nanometer wavelengths, that is not visible to the human eye. However, inexpensive sensitive wavelength converters are readily available for converting this light to the visible region. The optical cable here is constructed with outside protective material that is transparent to these wavelengths. Figs. 1A and 1B are end views of two tight buffer fiber-optic cable construction options that illustrate the principle. Fig. 1A is a two-fiber cable, and Fig. 1B is a four-fiber cable. The fibers 1 are coated and surrounded by a protective plastic primary buffer jacket 2 made of HYTREL* or similar material. Construction of optical cable up to thi...