PURPOSE: To prepare a parent material of SiO2-based optical fiber of high quality at low temp. and high forming rate by oxidizing or hydrolyzing perchloro polysilane in the presence of compd. of B, Ge, P, or F, etc. and depositing formed fine particles on a substrate.
CONSTITUTION: Perchloro polysilane expressed by the general formula: SinCl2n+2 as an Si compd. for the main starting material gas, and a B, Ge, P, or F, etc. compd. such as BBr3, GeCl4, POCl3, SiF4, as dopant gas, are introduced into a reaction chamber held at high temp. with oxyhydrogen flame or hot gas stream in accompany with O2, air, inert gas, etc. to form fine particles by oxidation or hydrolysis, and formed fine particles are deposited in the fused state on a substrate. Preferred perchloro polysilane is Si2Cl6, Si3Cl8, or a mixture thereof. A porous glass body obtd. by the deposition of the fused fine particles is heated further for defoamation or solidification, thus, a parent material for optical fiber is obtd.
TAJIMA YOSHIYUKI
ISOTANI KAZUYOSHI
HIROSE SUMIO
Next Patent: PREPARATION OF PARENT MATERIAL FOR OPTICAL FIBER