APPARATUSES AND METHODS FOR LASER PROCESSING TRANSPARENT WORKPIECES USING NON-AXISYMMETRIC BEAM SPOTS

摘要

A method for laser processing a transparent workpiece includes forming a contour line that includes defects, by directing a pulsed laser beam output by a beam source through an aspheric optical element positioned offset in a radial direction from the beam pathway and into the transparent workpiece such that the portion of the pulsed laser beam directed into the transparent workpiece generates an induced absorption within the transparent workpiece that produces a defect within the transparent workpiece. The portion of the pulsed laser beam directed into the transparent workpiece includes a wavelength λ, an effective spot size w_o,eff, and a non-axisymmetric beam cross section having a minimum Rayleigh range Z_Rx,min in an x-direction and a minimum Rayleigh range Z_Ry,min in a y-direction. Further, the smaller of Z_Rx,min and Z_Ry,min is greater than F_Dπw_0,eff²/λ, where F_D is a dimensionless divergence factor comprising a value of 10 or greater.