Self-healing high-order harmonic generation from curved relativistic plasma mirrors with Bessel-Gaussian beams

Coherent focusing of high-order harmonic generation (HHG) from optically curved relativistic plasma mirrors provides a promising route to achieve unprecedented high intensities, opening up prospects to study phenomena occurring in extremely strong fields, the region of which is however limited within extremely small spatial and temporal scales. Here through three-dimensional particle-in-cell simulations we demonstrate HHG driven by Bessel-Gaussian beams exhibiting the intriguing feature of self-healing up to the relativistic and extreme nonlinear regime. This allows a secondary intensification of reflected fields after the focus of curved plasma mirrors and thus extends the high-intensity region in both space and time, beneficial for extreme field applications.