Fig. 1. D-scan measurements of the driving laser pulse. (a) Measured and (b) retrieved D-scan trace for the compressed broadband laser pulse. (c) Measured spectral intensity (blue) and retrieved spectral phase (red) of the laser pulse. (d) Retrieved temporal profile of the 5.2 fs laser pulse (blue) and the Fourier transform-limited pulse supported by the spectrum (dashed red).

Fig. 2. Experimental setup for generation and characterization of attosecond pulses. FM, focusing mirror; MA, motorized aperture; TM, toroidal mirror; DM, double mirror; TOF, time-of-flight spectrometer.

Fig. 3. Reflectivity of the Mo/Si multilayer coated two-segment mirror utilized as the spectral filter in the amplitude gating of the HHG as a function of photon energy.

Fig. 4. Retrieval of IAP and NIR pulses. (a) Measured and (b) retrieved FROG-CRAB trace of the IAP in the streaking field. (c) Reconstructed temporal profile of the IAP with an FWHM pulse duration of 86 attoseconds. (d) Reconstructed vector potential (blue) of the driving laser pulse and the 5.2 fs reference curve (red) according to the D-scan measurement.