Title:
METHOD AND APPARATUS FOR MANUFACTURING DOPED OPTICAL PREFORM
Document Type and Number:
Japanese Patent JPS62283840
Kind Code:
A
Abstract:
An optical fiber preform is formed by plasma chemical vapor deposition utilizing a plasma torch (10) that includes a chamber into which a plasma starting gas. such as argon, is introduced (30) and converted to a plasma by application of high frequency electromagnetic energy. A suitable entry port (34) is provided in the torch chamber to allow dopant material (36) in solid form to be introduced directly into the plasma for vaporization or ionization. The dopant material (36) passes into a lower temperature region where gaseous silica precursor gases are introduced (38,40) to undergo reaction in the presence of the vaporized dopant to form appropriately doped silica particles (16) for deposition onto a substrate (18). Solid dopants (36) of low volatility or vapor pressure may be used as dopants which could not otherwise be used in vapor deposition processes. The absence of hydrogen in the reaction dynamics results in a preform having greatly reduced hydroxyl ion content. If desired, a high-purity starting glass, rather than the precursor gases, can be introduced directly into the plasma to form the appropriately doped material.
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Inventors:
ROBAATO JIEI MANSUFUIIRUDO
Application Number:
JP11670087A
Publication Date:
December 09, 1987
Filing Date:
May 13, 1987
Export Citation:
Assignee:
POLAROID CORP
International Classes:
G02B6/00; C03B37/012; C03B37/014; C03B37/018; C23C16/513; (IPC1-7): C03B20/00; C03B37/018; G02B6/00
Attorney, Agent or Firm:
Asamura Akira
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