Malka’s Lab

Overcoming the dephasing limit in laser-wakefield acceleration promises allow for significantly more favorable scaling laws of achievable electron energy and to enable the acceleration of electrons with energies of over 100 GeV in existing laser facilities. One of the most promising solutions for achieving dephasing-free acceleration relies on structuring light with an axiparabola and spatio-temporal couplings. Here we show an experimental setup that yields such a structured pulse and demonstrate its ability to tune the on-axis intensity propagation velocity. Furthermore, we show that the wakefield generated by such a pulse is able to maintain the coherent structures necessary for accelerating electrons to relativistic energies.

Time and space envelope, frequency and wavelength distributions, polarization, and phase are quantities that define the properties of laser light. Controlling them opens up strategies for manipulating the properties of atoms in various media. At relativistic intensity, matter is rapidly transformed into a plasma state, which is modifying the lasers propagation, its absorption enabling the generation of intense magnetic and electric fields. In this context, structured light presents exciting, promising, and challenging opportunities for research. This review article aims to explain the concepts of structured light, their applications to real experiments at relativistic intensities, practical considerations, and some scientific perspectives.

High-power laser systems have opened new frontiers in scientific research and have revolutionized various scientific fields, offering unprecedented capabilities for understanding fundamental physics and allowing unique applications. This paper details the successful commissioning of the 1 PW experimental area at the Extreme Light Infrastructure-Nuclear Physics (ELI-NP) facility in Romania, using both of the available laser arms. The experimental setup featured a short focal parabolic mirror to accelerate protons through the target normal sheath acceleration mechanism. Detailed experiments were conducted using various metallic and diamond-like carbon targets to investigate the dependence of the proton acceleration on different laser parameters. Furthermore, the paper discusses the critical role of the laser temporal profile in optimizing proton acceleration, supported by hydrodynamic simulations that are correlated with experimental outcomes. The findings underscore the potential of the ELI-NP facility to advance research in laser-plasma physics and contribute significantly to high-energy physics applications. The results of this commissioning establish a strong foundation for experiments by future users.