Extremely high-aspect-ratio ultrafast Bessel beam generation and stealth dicing of multi-millimeter thick glass

We report on the development of an ultrafast beam shaper capable of generating Bessel beams of high cone angle that maintain a high intensity hot spot with subwavelength diameter over a propagation distance in excess of 8mm. This generates a high intensity focal region with extremely high aspect ratio exceeding 10000:1. The absence of intermediate focusing in the shaper allows for shaping very high energies, up to Joule levels. We demonstrate a proof of principle application of the Bessel beam shaper for stealth dicing of thick glass, up to 1cm. We expect that this high energy Bessel beam shaper will have applications in several areas of high intensity laser physics.