Specialty Optical Fibers Handbook

Chapter 3

Overview of Materials and

Fabrication Technologies

John B. MacChesney,

1

Ryan Bise,

1

and Alexis Me

´

ndez

2

1

OFS Bell Labs, Murray Hill, New Jersey

2

MCH Engineering LLC, Alameda, California

3.1 DOUBLE-CRUCIBLE TECHNIQU E

The first attempt at producing high-purity glass, the so-called ‘‘double-

crucible technique,’’ proceeded along the lines of conventional glass melting

but used specially prepared constituents [1, 2]. Soda-lime-silicate and sodium-

borosilicate glasses were made from materials purified to parts-per-billion (ppb)

levels of transition metal impurities by ion exchange, electrolysis, recrystalliza-

tion, or solvent extraction. These starting ...