Giant half-cycle attosecond pulses

TL;DR

This paper demonstrates the generation of extremely short, intense half-cycle attosecond pulses using a double foil target irradiated by few-cycle laser pulses, enabling new ultrafast experimental possibilities.

Contribution

It introduces a novel method to produce 50 attosecond half-cycle pulses with high electric fields using a double foil target and intense laser irradiation.

Findings

Produced 50 as duration pulses with up to 10^13 V/m fields.

Achieved relativistic electron sheet formation for pulse generation.

Enabled potential for new attosecond pump-probe experiments.

Abstract

Half-cycle picosecond pulses have been produced from thin photo-conductors, when applying an electric field across the surface and switching on conduction by a short laser pulse. Then the transverse current in the wafer plane emits half-cycle pulses in normal direction, and pulses of 500 fs duration and 1e6 V/m peak electric field have been observed. Here we show that single half-cycle pulses of 50 as duration and up to 1e13 V/m can be produced when irradiating a double foil target by intense few-cycle laser pulses. Focused onto an ultra-thin foil, all electrons are blown out, forming a uniform sheet of relativistic electrons. A second layer, placed at some distance behind, reflects the drive beam, but lets electrons pass straight. Under oblique incidence, beam reflection provides the transverse current, which emits intense half-cycle pulses. Such a pulse may completely ionize even heavier atoms. New types of attosecond pump-probe experiments will become possible.