Refractive plasma optics for relativistic laser beams

The high intensities reached today by powerful lasers enable us to explore the interaction with matter in the relativistic regime, unveiling a fertile domain of modern science that is pushing far away the frontiers of plasma physics. In this context, refractive-plasma optics are being utilized in well established wave guiding schemes in laser plasma accelerators. However, their use for spatial phase control of the laser beam has never been successfully implemented, partly due to the complication in manufacturing such optics. We here demonstrate this concept which enables phase manipulation near the focus position, where the intensity is already relativistic. Offering such flexible control, high-intensity high-density interaction is becoming accessible, allowing for example, to produce multiple energetic electron beams with high pointing stability and reproducibility. Cancelling the refractive effect with adaptive mirrors at the far field confirms this concept and furthermore improves the coupling of the laser to the plasma in comparison to the null test case, with potential benefits in dense-target applications.

Automated summary

The high intensities reached by powerful lasers today allow us to explore the interaction with matter in the relativistic regime, pushing the frontiers of plasma physics. Refractive-plasma optics are being used in laser plasma accelerators, but their use for spatial phase control of the laser beam has not been successful due to manufacturing complications. However, this concept has now been successfully demonstrated, enabling phase manipulation near the focus position, where the intensity is already relativistic, and offering flexible control for high-intensity high-density interactions.