Generation of intense isolated attosecond pulses with high spatiotemporal quality by two-color polarization-gating Bessel–Gauss beams

We propose an efficient approach to generate intense isolated attosecond pulses, which is based on the double optical gating mechanism of using two-color polarization-gating driving pulses. A relatively intense second harmonic field is added to the fundamental pulse and microscopically enhances the high harmonic emission insider polarization-gating. In the high harmonic generation, Bessel–Gauss beams are employed to macroscopically improve the propagation dynamics in both temporal and spatial domains. The results shows that, compared with the traditional Gaussian case, Bessel–Gauss beams can produce well phase-matched supercontinuum in the plateau region, and efficient isolated attosecond pulses with high spatiotemporal quality can be obtained successfully.