Polarization control of high-order harmonic generation via the interference effect between high-symmetry points in solid

<p indent="0mm">Elliptic harmonics with the same helicity across a wide spectral range are key points for the generation of elliptically polarized ultrashort radiation sources, which are highly demanded in ultrafast spectroscopy of chirality-sensitive dynamics. In this paper, we propose an approach for the generation of elliptic harmonics with the same helicity across a wide spectral range. This method utilizes the interference effect of solid high-order harmonics radiated from different regions in the reciprocal space. We demonstrate this scheme by taking the high-harmonic generation of graphene in corotating bicircular laser fields as an example. The results show that one of the helicity components of harmonics can be significantly suppressed by destructive interference. Meanwhile, the component with opposite helicity is enhanced and dominates the harmonic spectrum due to constructive interference. The proposed method has the potential to generate elliptically polarized attosecond pulses.