Separation of transparent workpieces

Abstract

A method is provided for preparing transparent workpieces for separation. The method includes generating aligned filament formations extending transversely through the workpiece along an intended breaking line using ultra-short laser pulses.

What is claimed is: 
     
         1 . A method for separating a workpiece by focused laser radiation, comprising:
 exposing the workpiece to a first atmosphere including protective gas;   directing ultra-short pulsed laser radiation onto the workpiece, the workpiece being transparent in a range of wavelengths of the laser radiation to cause a filamentary material modification in depth in the workpiece;   moving the workpiece and/or laser radiation with respect to one another to define a separation area in the workpiece;   exposing, after the laser irradiation, the workpiece to a second atmosphere including a content of hydroxyl (OH) ions that is higher than that of the protective gas atmosphere;   breaking the workpiece along the separation area defined by the material modification.   
     
     
         2 . The method as claimed in  claim 1 , wherein the workpiece comprises toughened glass or glass ceramics. 
     
     
         3 . An apparatus for separating glass or glass ceramics by focused laser radiation, comprising:
 a workpiece chamber for accommodating the glass or glass ceramics;   a workpiece feeder that feed the glass or glass ceramics into the workpiece chamber;   an ultra-short pulsed laser light source that generates a filamentary material modification in depth in the glass or glass ceramics by laser irradiation;   a displacing device that moves the workpiece and/or the laser light source relative to each another;   wet steam feed device that feeds a gas stream into the workpiece chamber; and   a separating device that separates the workpiece along a separation line defined by the material modification.