Frequency gating to isolate single attosecond pulses with overdense plasmas using particle-in-cell simulations

Abstract

We present the isolation of single attosecond pulses for multi-cycle and few-cycle laser pulses from high harmonic generation in overdense plasmas, calculated with particle-in-cell simulations. By the combination of two laser pulses of equal amplitude and a small frequency shift between them, we demonstrate that it is possible to shorten the region in which the laser pulse is most intense, therefore restricting the generation of high harmonic orders in the form of attosecond pulses to a narrower time window. The creation of this window is achieved due to the combination of the laser pulse envelope and the slow oscillating wave obtained from the coherent sum of the two pulses. A parametric scan, performed with particle-in-cell simulations, reveals how the pulse isolation behaves for different input laser pulse lengths and which are the optimal frequency shifts between the two laser pulses in each case, giving the conditions for having a good isolation of an attosecond pulse when working with laser-plasma interaction in overdense targets.

Simulation Study of a Bright Attosecond γ-ray Source Generation by Irradiating an Intense Laser on a Cone Target

“…In addition, the γ-ray source based on laserplasma interactions is different from the traditional accelerator radiation source: it has the advantages of a high brightness and compact construction, and has important application prospects in basic scientific research, medical treatment, industry and some other fields [12,13]. The interaction of a relativistic high-intensity laser with a solid target is considered as a promising method [14] to improve the intensity of attosecond light sources, including the mechanisms of the coherent wake emission [15], the relativistic oscillatory mirror model (ROM) [16] and the coherent synchrotron emission (CSE) [17].…”