Attosecond Pulse Amplification in a Plasma-Based X-Ray Laser Dressed by an Infrared Laser Field

TL;DR

This paper proposes a plasma-based X-ray laser technique that amplifies attosecond pulse trains generated by high-harmonic generation, using IR field modulation to achieve significant amplification and pulse isolation.

Contribution

It introduces a novel method to amplify attosecond pulses in a plasma medium by IR-induced frequency modulation, enabling substantial amplification and pulse isolation.

Findings

Amplification of attosecond pulse trains by two orders of magnitude.

Pulse durations can be as short as 100 attoseconds.

Single pulse isolation is feasible during amplification.

Abstract

We suggest a technique to amplify a train of attosecond pulses, produced by high-harmonic generation (HHG) of an infrared (IR) laser field, in an active medium of a plasma-based X-ray laser. This technique is based on modulation of transition frequency of the X-ray laser by the same IR field, as used to generate the harmonics, via linear Stark effect, which results in redistribution of the resonant gain and simultaneous amplification of a wide set of harmonics in the incident field. We propose an experimental implementation of the suggested technique in active medium of C5+ ions at wavelength 3.4 nm in the "water window" range and show the possibility to amplify by two orders of magnitude a train of attosecond pulses with pulse duration down to 100 as. We show also a possibility to isolate a single attosecond pulse from the incident attosecond pulse train during its amplification in optically deep modulated medium.