Bell Telephone Laboratories

At&t Bell Laboratories

Arthur D Pearson

Paul Joseph Lemaire

Paul B O'Connor

Paul D Lazay

John Burnette MacChesney

Paul H Schmidt

Klaus Jurgen Bachmann

Robert L Barns

Arthur R Tynes

Suzanne Rose Nagel

A method of forming optical fibers with minimal contamination from ambient air is disclosed. In the inventive method a gas stream is introduced into a rotating structure by means of a rotating seal. The rotating seal comprises a rotating member seated within a stationary member. Counterflowing gases are flowed through the clearance region between the rotating and stationary members to prevent seepage of ambient air into the gas stream.

Optical fiber fabrication process

A low-loss single mode fiber with low total dispersion within the wavelength range 1.25-1.385 .mu.m and low added cabling loss is disclosed. The fiber has relatively high .DELTA. to assure low cabling loss. The high .DELTA. is obtained, however, without paying a cost in high material dispersion by providing at least 20 percent of the .DELTA. by down-doping of the fiber cladding.

Low dispension single mode fiber

Low dispersion single mode fiber

An optical fiber fabrication method and apparatus are described which are capable of producing reproducible and uniform layers of fiber quality glass. The formation of a saturated stream of glass precursor vapor by condensation allows for the delivery of calibrated predetermined quantities of vapor to an appropriate fiber fabrication apparatus, thereby permitting improved fabrication characteristics.

Optical fiber fabrication method and apparatus

Glass tubes which form an integral part of optical fiber preforms from which optical fibers are drawn are fabricated from tubular structures comprising amorphous powdery particles. The tubular structures are heated so as to fuse the particles thereby yielding a transparent tubular glass structure of optical fiber quality. During the fusing step, the structure is substantially constrained against shrinkage in both the radial and longitudinal direction thereby yielding a glass tube with improved dimensional characteristics.

Glass fiber optical-waveguides consisting of a metal oxide-silicate glass core and silica cladding are produced according to the invention by means of a metal evaporation technique. An evacuated fused silica tube containing an evaporated metal deposit is heated to temperatures sufficient to form a uniform metal silicide layer on its inner surface. This layer is then oxidized and reacted with the silica tubing at elevated temperatures to form a metal oxide-silica glass layer. The tube is then collapsed to give a solid rod preform with a metal oxide-silica glass core. Fibers drawn from such preforms exhibit a graded refractive index profile and low loss. The details of the fabrication technique are described, and a representative loss spectrum is presented.

Growing community of inventors

Bernardsville, NJ, United States of America

Arthur D Pearson