Elongated semi-finished optical laminated quartz glass material, for optic fibers, feeds a coaxial compound structure of an outer cylinder with an inner core rod into a heating zone to collapse the cylinder at a drawing temperature

摘要

To produce a semi-finished optical component, of laminated quartz glass, a compound structure (30) is elongated as a coaxial hollow cylinder (1) and a core rod (4) with a unit (35) to fix the core rod within the interior (2) of the cylinder. The compound structure is advanced continuously into one end (11) of a heating zone, which raises it to a drawing temperature for the cylinder interior to collapse by sections as the semi-finished optical material is drawn out. The fixing unit is surrounded by a seal (36) at the lower end of the hollow cylinder, into the heating zone, of a quartz glass with a lower viscosity than that of the hollow cylinder at the drawing temperature through dosing with fluorine, germanium, phosphor or boron.