Process for collapsing a glass tube, in particular for the production of optical waveguides in the form of glass fibres

摘要

The collapsing of glass tubes (1) having a tough internal coating (6), for example of pure SiO2, is associated with difficulties in the case of conventional heating from the outside through the outer surface (11) of the tube since the shrinkage rate is low. The novel process is intended to allow such tubes to be collapsed relatively easily and quickly. To this end, the internal surface (53) of the shrinkage zone is additionally irradiated in the longitudinal axial direction of the tube (1) with the laser radiation (8) from a CO2 laser. This allows the shrinkage rate to be drastically increased. Production of optical waveguides. <IMAGE>