0000000000856019
AUTHOR
Ismail Ouadghiri-idrissi
Four-wave mixing control in the filamentation of ultrafast Bessel beams via longitudinal intensity-shaping
International audience; Bessel beams exploit conical energy flow to yield near-uniform intensity along a line focus which has been shown to be extremely attractive for laser processing in dielectrics. At high power, however, the nonlinear Kerr effect is known to induce significant oscillations of the on-axis intensity which is deleterious for machining applications. Here, we show through theory and numerical modelling how this problem can be understood and overcome by appropriate spatial phase shaping of the input profile. Our results also solve the longstanding problem related to the nonlinear Bessel beam dynamics seen at an air-dielectric interface.
Control of nonlinear instabilities in Bessel beams using shaped longitudinal intensity profiles
International audience; We show that tailored longitudinal intensity shaping of a non-diffracting Bessel beam can strongly reduce four wave mixing induced oscillations and stabilize nonlinear propagation at ablation-level intensities