Anomalous Relativistic Emission from Self-Modulated Plasma Mirrors

Abstract

The interaction of intense laser pulses with plasma mirrors has demonstrated the ability to generate high-order harmonics, producing a bright source of extreme ultraviolet (XUV) radiation and attosecond pulses. Here, we report an unexpected transition in this process. We show that the loss of spatio-temporal coherence in the reflected high-harmonics can lead to a new regime of highly-efficient coherent XUV generation, with an extraordinary property where the radiation is directionally anomalous, propagating parallel to the mirror surface. With analytical calculations and numerical particle-in-cell simulations, we discover that the radiation emission is due to laser-driven oscillations of relativistic electron nanobunches which originate from a plasma surface instability induced by collisionless absorption of the laser.

6 pages, 3 figures

References in corpus (3)

• Laser acceleration of ion bunches at the front surface of overdense plasmas
• Optical Properties of Relativistic Plasma Mirrors
• Soft X-ray harmonic comb from relativistic electron spikes

Cited by in corpus (4)

• Compact Petawatt-Class Laser Wakefield Acceleration with Plasma Telescope
• Visualization of high-intensity laser-matter interactions in virtual reality and web browser
• Collimated $\gamma$-flash emission along the target surface irradiated by a laser at non-grazing incidence
• Bright coherent attosecond X-ray pulses from beam-driven relativistic mirrors