Carrier-envelope phase effects on the broadband spectrum of high-order harmonics driven by a few-cycle laser pulse

In summary, we carefully investigated the dependence of the properties of an EUV emission driven by a sub-10-fs laser pulse on the CEP. We found that a CEP-sensitive structure appeared in a broad wavelength range from the ldquoplateaurdquo to the ldquocut-offrdquo region. An oscillation structure appears in the ldquocut-offrdquo region, and the emission spectra exhibit complicated fine structure near the highest end of the ldquoplateaurdquo. A model calculation revealed that this fine structure is the evidence of quantum interference between wave packets with two different electron trajectories.