Femtosecond laser material processing with spatially tailored pulses to control filamentation and enhance laser-plasma interaction

International audienceFemtosecond laser processing is a versatile and reproducible technology with a large potential for mass micro-nano fabrication. However, the control of energy deposition within transparent materials is a challenge because of the nonlinear character of the propagation of laser light into the medium to ablate. We have recently developed several strategies to overcome this problem, based on the use of solutions that are propagation-invariant, even in the nonlinear regime, such as Bessel beams, accelerating beams and Bessel vortices. These beams allow for novel technological applications: curved edge profiling, high-aspect ratio drilling in single shot and extreme material compression.Interestingly, the long range of laser-plasma interaction within these beams also provide novel insights in the laser-plasma interaction within the bulk of materials. We have developed an experimental strategy to enable non-ambiguous and direct comparison with nonlinear propagation models. We uncover reasons for extreme confinement of the laser-matter interaction