Method of preparing a foreproduct for the production of an optical lightconductor

US4045198A · kind A · utility

Assignee

• Heraeus Quarzschmelze GmbH · DE

Inventors

• Karlheinz Rau · Hanau, DE
• Albert Muhlich · Frankfurt, DE
• Fritz Simmat · Gelnhausen, DE
• Norbert Treber · Kriftel, DE

Key dates

• Filing date: Aug 24, 1976
• Grant date: Aug 30, 1977
• Expiry date: Aug 24, 1996

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S65/16
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

There is disclosed a process for preparing a foreproduct useful in the production of an optical self-focusing lightconductor in which the index of refraction of the lightconductor diminishes with increasing distance from the conductor axis such that, when plotted against the conductor diameter, the refractive index curve is parabolic and the apex of the parabola lies over the center of the conductor diameter wherein a plurality of layers of doped silica are deposited on a cylindrical support, the layers being formed of a mixture of a vaporous silicon compound and a vaporous doping agent at elevated temperature. The invention involves depositing at least one layer of undoped silica between layers of doped silica and following each deposition of each doped or undoped silica layer by heating step in which the material is heated to a temperature of at least 900.degree. C to vitrify the same. Each layer is deposited in a thickness ranging from 0.1 to 20 .mu.m.