Improved polarization gating scheme on attosecond source generation

Abstract

ABSTRACTAn improved polarization gating scheme on attosecond X-ray pulse generation from high-order harmonic generation has been investigated. It is found that by properly adding a linearly polarized pulse to the circularly polarized pulse, the harmonic spectrum is remarkably enhanced and controlled, leading to an efficient generation of the ultra-broadband supercontinuum covered by the spectrum range from ultraviolet to X-ray. Classical and the quantum time–frequency analyses have been shown to explain the harmonic emission process. Moreover, from analyzing the harmonic phases, we see that the phases of the generated harmonics are almost linear, which is beneficial to the attosecond pulse generation. As a result, a series of phase-steady and wavelength-tunable sub-50 as X-ray pulses can be obtained.