The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 10, 1987
Filed:
Feb. 08, 1985
Paul F Glodis, Atlanta, GA (US);
Terrence A Lenhan, Chamblee, GA (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A single mode optical fiber comprises a core, a first cladding surrounding the core, and a second cladding surrounding the first cladding. It also comprises a third cladding region (or index 'ring'). The core, has radius a and refractive index n.sub.c, the first, second, and third cladding regions have inner radii, R.sub.1i, R.sub.2i, and R.sub.3i, outer radii R.sub.1o, R.sub.2o, and R.sub.3o, and indices n.sub.1, n.sub.2, n.sub.3, respectively. The fiber has n.sub.1 <n.sub.3, R.sub.1o .ltoreq.R.sub.3i, R.sub.3o .ltoreq.R.sub.2i. In preferred embodiments, a=R.sub.1i, R.sub.1o =R.sub.3i, R.sub.3o =R.sub.2i. Appropriate choice of ring parameters can result in a lowering of the cut-off wavelength of the fiber, or in fiber that is less sensitive to macrobending than similar prior art fiber lacking an index ring, without substantial change in fiber parameters that depend primarily on the waveform in the core. An optical fiber communications system comprising the inventive fiber is also disclosed.