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:
Aug. 21, 1979
Filed:
Oct. 14, 1977
Arnaud DE Panafieu, Paris, FR;
Michel Villard, Paris, FR;
Christiane Baylac, Paris, FR;
Michel Favre, Paris, FR;
Thomson-CSF, Paris, FR;
Abstract
A process yielding a glass blank in the form of a rod intended for drawing an optical fiber of the kind of self-focussing fiber i.e. having a radial refractive index gradient, having features (substantially transparency or transmission efficiency) lower than those of the fibers intended for long distance communication but sufficient for middle distance transmission, and which exhibits a lower cost than known processes. In a first stage a phase separation yields a 'hard' phase (rich in silicon) and a 'soft' phase (poor in silicon and rich in impurities) due to the drawing of a rod from a bath of molten glass through a cooling system having a strong temperature gradient and creating a radial refractive index gradient. In a second stage the soft phase is leached, eliminating the impurities contained in the soft phase but keeping safe the radial gradient. In a third stage a consolidation treatment is a pure annealing treatment rendering the hard phase more homogeneous.