Selection of quantum path in high-order harmonics and isolated sub-100 attosecond generation in few-cycle spatially inhomogeneous laser fields |
(a) The time-frequency distribution of the HHG spectra corresponds to the blue line ( ε = 0.0015 a.u.) as shown in Fig. 8(c) . (b) The temporal profiles of the as pulses generated by superposing the harmonics from 900th to 1000th order. o.c. denotes the optical cycle. |