Optical waveguide preform fabrication

摘要

Powdered silica optionally mixed with dopant (e.g. GeO2) is introduced via dosing feeder 2 coaxially into a ring- or tube-shaped heating device such as oxyhydrogen burner 4, 5, 6, where the powder melts/evaporates and may be treated with a gas (e.g. chlorine) to remove hydroxyl groups and impurities. The glass is deposited from the liquid/vapour phase onto the end of rotating substrate 13 to produce preform 17 which may be coated in a second deposition process using burner 18.