Fabrication of lightguide soot preforms

摘要

A glass soot deposition torch (30; FIG. 2) having gas passages arranged to provide an inner (34) and outer (36) flame front is disclosed in which the temperature of the inner front is higher than the outer front. A passage is located within the outer front (36) through which glass soot (32) is directed onto the surface of a growing soot-form core (38).