Generation of isolated attosecond pulses with a specific waveform two-color laser field

We theoretically propose a new method for generating intense isolated attosecond pulses during high-order harmonic generation (HHG) process by accurately controlling electron motion with a two-color laser field, which consists of an 800-nm, 4-fs elliptically polarized laser field and a 1400-nm, ~43-fs linearly polarized laser field. With this method, the supercontinua with a spectral width above 200 eV are obtained, which can support a ~15-as isolated pulse after phase compensation. Classical and quantum analyses explain the controlling effects well. In particular, when the pulse duration of the 800-nm laser field increases to 20-fs, sub-100-as isolated pulses can be obtained even without any phase compensation.