Abstract: A conventional method for the production of a quartz glass blank comprises a method step in which SiO2 particles are generated by means of a series of deposition burners and deposited on a cylinder outer surface of a support, rotating about the longitudinal axis thereof to form a cylindrical porous SiO2 soot body. The surface temperature of the forming soot body is altered by means of a temperature adjustment body. According to the invention, the above may be developed to give an economical method for the production of an SiO2 soot body with low axial thickness variations and to provide a device of simple construction of the same, whereby the temperature adjustment body is applied in the form of a planar element running along a significant part of the SiO2 soot body, which either acts on the soot body surface as a temperature-screening homogeneous heat sink or as a homogeneous reflector for temperature raising, by means of heat radiation.

Abstract: The invention relates to a method for manufacture of a quartz glass preform for an optical fibre consisting of the following steps: preparation of a hollow cylinder made of porous quartz glass which exhibits an inner layer with a doping substance which increases the refractive index of quartz glass and an outer layer surrounding the inner layer, with a lower refractive index, and collapse of the hollow cylinder characterised by collapse of the porous hollow cylinder onto a quartz glass rod containing the doping substance.

Abstract: According to a prior art method for producing a cylindrical component comprised of silica glass, a cylinder comprised of a softened silica glass mass is drawn in a predetermined drawing direction along a drawing axis by means of a drawing device which acts upon said cylinder. The aim of the invention is to provide a method which prevents, to the greatest possible extent, warping of the drawn cylinder and other deviations from the ideal cylinder dimensions and to prevent, to the greatest possible extent, the outer surface of the drawn cylinder from being touched. To these ends, the invention provides that the drawing device comprises a plurality of guide elements which are arranged one behind the other along the drawing axis, and which can be displaced independently of one another in a drawing direction and in a direction opposite thereto.