Near-circularly polarized isolated attosecond pulse generation from a current-carrying state of Ar atom by two-color cross-linearly polarized laser fields

Abstract

We theoretically propose an efficient method to generate near-circularly polarized isolated attosecond (as) pulses (NCP-IAPs) from a current-carrying state of Ar atom driven by two-color cross-linearly-polarized laser fields. We find that the ellipticity of high harmonics can be controlled by adjusting the crossing angle of two linearly polarized lasers and the near-circularly polarized supercontinuum harmonics are obtained when the crossing angle is around 140°. Furthermore, we can produce the NCP-IAPs with the ellipticity up to 0.94 and the shortest one achieves 196 as. This work demonstrates the possibility for generating the NCP-IAPs using a current-carrying state of atoms driven by two-color cross-linearly-polarized laser fields.