Fig. 1. Photon energy and dispersion of high-order harmonic radiation near 98 eV. (a) XUV photon energy changed with the electron ionization time; (b) XUV intrinsic group delay dispersion (GDD)

Fig. 2. Properties of 300 nm Zr foil. (a) Transmissivity; (b) phase; (c) GD; (d) GDD

Fig. 3. Properties of Mo and Sn foil. (a) 150 nm Mo transmissivity; (b) 150 nm Mo GDD curve; (c) 400 nm Sn transmissivity; (d) 400 nm Sn GDD curve

Fig. 4. High-order harmonic continuous spectrum generated in a neon target and isolated attosecond pulse of 38 as obtained by numerical simulation using 150 nm Mo foil to compensate the intrinsic chirp. (a) HHG spectrum and phase; (b) time domain pulse shape calculated by Fourier transform

Fig. 5. Non-collinear attosecond streak camera, including the optics for generation and detection of the attosecond pulses. Insets: (a) Interference fringes formed by the driving and detecting beams near the hole mirror; (b) beam spot at TOF when the driving and detecting pulses overlap in time and space; (c) calculated imaging positions of the flat field grating