process for the production of a protective layer on the basis of amorphous boron on an optical fiber and optical fiber equipped with this coating

摘要

PCT No. PCT/FR95/01107 Sec. 371 Date Apr. 24, 1996 Sec. 102(e) Date Apr. 24, 1996 PCT Filed Aug. 23, 1995 PCT Pub. No. WO96/06055 PCT Pub. Date Feb. 29, 1996A method of applying an amorphous boron-based protective coating to an optical fiber comprising an optical core enclosed in optical cladding, both made of a silica-based material, wherein the boron is applied to the surface of said optical fiber chemically from the vapor phase at a temperature lying in the range 1050 DEG C. to 1250 DEG C., by reducing boron chloride BCl3 by means of hydrogen H2. The amorphous boron protective coating imparts mechanical protection to the fiber, and enhanced abrasion resistance, enabling the fiber to be used in optical cables of high capacity and that are highly compact. The thickness of the resin coating can be about half that required when a carbon protective coating is used, and can even be eliminated. The coating further provides sealing properties comparable to those provided by a carbon coating.