Optimization of Bessel beam optics for high-quality glass cutting

Diffraction-free Bessel beams have been of great interest for laser processing of transparent materials. Compared to traditional Gaussian beams, the Bessel-Gauss beams has thin focus profile which remains invariant over much longer propagation distances. Achieved in such a way extended depth of focusing in combination with precise energy deposition has opened diverse promising applications in display industry. Here we have analyzed the effect of conical angle on the interaction of Bessel beam with a display panel having multiple organic and inorganic layers on a glass. First, we have shown that experimentally observed thermal damages in display emission area are caused by long Bessel beam tails in contrast to Gaussian beams, where the damages are driven by heat diffusion. Second, we study the role of Kerr effect and arising instabilities in non-linear propagation through the glass substrate. Using numerical simulations and in-situ pump-probe microscopy methods we gain the knowledge of primary steps of energy deposition with high temporal and spatial resolution. At high laser intensities and low numerical aperture, the original Bessel beam profile can be de-stabilized leading to the longitudinal fluctuation of intensity. The laser processing with high conical angle Bessel beams is much more resistant to undesirable beam self-focusing and phase self-modulation effects, which enables us to achieve the regime of optimal laser energy deposition for high-quality glass cutting.