Gas position effect on single attosecond pulse generation in crossed metal nanostructure

Abstract

An effect method to obtain the single attosecond pulses (SAPs) by using the inhomogeneous polarization gating (PG) technology in the crossed metal nanostructure has been proposed and investigated. It is found that by properly injecting the gas into the negative position of the nanostructure, the emitted harmonics at the very highest orders used for the SAPs only occurs at one side of the region inside the nanostructure. As a result, not only the extension of the harmonic cutoff can be achieved, but also the modulations of the harmonics can be decreased. Further, with the introduction of a weak near-infrared field, the harmonic yield can be enhanced by 3.5 orders of magnitudes in comparison with that from the single PG technology. Finally, by superposing the selected harmonics from the inhomogeneous PG scheme, a 32 as SAP with the high signal intensity can be obtained.