Generation of isolated attosecond pulses in bowtie-shaped nanostructure with three-color spatially inhomogeneous fields |
(a) The ionization probability obtained from the three-color inhomogeneous field at g = 18 nm. (b) The harmonic spectra (red line) in inhomogeneous field and the spectra (green line) in homogeneous field. (c) The corresponding time–frequency distribution in inhomogeneous field. |