Helicity of harmonic generation and attosecond polarization with bichromatic circularly polarized laser fields

Zhang Jun^{1, 2}, Qi Tong², Pan Xue-Fei², Guo Jing², Zhu Kai-Guang^{1, †}, Liu Xue-Shen^2,

Attosecond pulse trains with the intensity ratios γ ′ E = 1.0 generated by superposing the harmonics (a) from 30th to 40th order and (b) from 40th to 50th order. Attosecond pulse trains with the intensity ratios γ ′ E = 2.0 generated by superposing the harmonics (c) from 37th to 47th order and (d) from 60th to 70th order. The other laser parameters are the same as those in Fig. 2.