Abstract: One aspect relates to a method for producing an optical blank from synthetic quartz glass by vitrifying and shaping a porous, cylindrical SiO2 soot body having a longitudinal axis, in a heating zone including a melt mold with bottom plate. The SiO2 soot body vitrified in the heating zone at a vitrification temperature so as to form a full cylindrical, completely vitrified, transparent quartz glass body. Subsequently, the vitrified quartz glass body is shaped by softening in the melt mold at a softening temperature so as to form a viscous quartz glass mass which partly fills the volume of the melt mold, and cooling the quartz glass mass and removal from the melt mold so as to form the optical blank. During shaping in the melt mold, the full cylindrical quartz glass body is brought into contact by way of controlled supply with a centering means of the bottom plate.

Abstract: One aspect relates to a method for producing an optical blank from synthetic quartz glass by vitrifying and shaping a porous, cylindrical SiO2 soot body having a longitudinal axis, in a heating zone including a melt mold with bottom plate. The SiO2 soot body vitrified in the heating zone at a vitrification temperature so as to form a fully cylindrical, completely vitrified, transparent quartz glass body. Subsequently, the vitrified quartz glass body is shaped by softening in the melt mold at a softening temperature so as to form a viscous quartz glass mass which partly fills the volume of the melt mold, and cooling the quartz glass mass and removal from the melt mold so as to form the optical blank. During shaping in the melt mold, the fully cylindrical quartz glass body is brought into contact by way of controlled supply with a centering means of the bottom plate.