Generation of elliptical isolated attosecond pulse from oriented $\textrm{H}_{2}^{+}$ in a linearly polarized laser field

Abstract

Abstract We investigate the ellipticity of the high-order harmonic generation from the oriented $\textrm{H}_{2}^{+}$ exposed to a linearly polarized laser field by numerically solving the two dimensional time-dependent Schr$\ddot{\textrm{o}}$dinger equation (2D TDSE). Numerical simulations show that the harmonic ellipticity is remarkably sensitive to the alignment angle. The harmonic spectrum is highly elliptically polarized at a specific alignment angle $\theta = 30^\circ $, which is insensitive to the variation of the laser parameters. The position of the harmonic intensity minima indicates the high ellipticity, which can be attributed to the two-center interference effect. The high ellipticity can be explained by the phase difference of the harmonics. The results that we obtain facilitates the synthesis of a highly elliptical isolated attosecond pulses with duration down to 65 as, which can be served as a powerful tool to explore the ultrafast dynamics of molecules and study chiral light-matter interaction.