Corning Incorporated
METHODS FOR ADJUSTING BEAM PROPERTIES FOR LASER PROCESSING COATED SUBSTRATES

Abstract:

A method of laser processing a coated substrate having a coating later disposed on a transparent workpiece that includes determining an optical characteristic of the coating layer and selecting a beam path for a pulsed laser beam based on the optical characteristic. The beam path is selected a polarization-adjusting beam path and a frequency-adjusting beam path. The method also includes directing the pulsed laser beam down the selected beam path to form a modified pulsed laser beam and directing the modified pulsed laser beam into the transparent workpiece, where the modified pulsed laser beam forms a laser beam focal line that induces absorption in the transparent workpiece to produce a defect in the transparent workpiece. The laser beam focal line includes a wavelength .lamda., a spot size w.sub.o, and a Rayleigh range Z.sub.R that is greater than F D .times. .pi. .times. .times. w o 2 .lamda. , ##EQU00001## where F.sub.D is a dimensionless divergence factor.