Diffraction Limited Harmonic Emission from Laser Produced Plasmas

Abstract

High order harmonic generation (HOHG) from intense laser — solid density interactions has emerged as a promising route to the generation of attosecond pulses extending to keV energies. With efficiency of the nth harmonic, η _n , scaling as ~ n ^−2.5− n ⁻³ in the relativistic limit up to a maximum order n _max~ 8^1/2γ³ (where γ is the maximum relativistic Lorentz factor of the oscillating plasma surface), the potential for a bright solution to attosecond science is a distinct possibility. Some of the recent work performed in the field verifies for the first time that the exceptional coherence properties of the driving laser can be transferred directly to the high harmonic orders produced when plasma surfaces are driven to relativistic velocities under the action of intense laser pulses.