| For measuring the dynamic process of electrons around the atomic nucleus,it is necessary to have a camera which shutter speed is shorter than electron orbital period.To date,the attosecond pule is seem as the fastest camera to steer and control the motion of electrons over the length scale of only a few angstrom.The cutting edge atto-second laser technology leads to the breakthrough to 24 as pulse generation,which is equal to the orbital period of hydrogen atom’s electron.while in that regime,the current attosecond pulse reconstruction schemes are not reliable.Based on systematic investigation,we developed a dynamic streaking model for ultrashort photoelectron pulses,and a numeric method to retrieve their pulse-lengths and chirps.The main results and innvations of the dissertation includes:1.By photoelectron dynamic streaking model,we simulated the streaking spectrum with different attosecond pulses.Through comparing the simulated spectrums,We revealed the association between pulse linear chirp and distribution of local intensity maximum in streaking spectrum.2.We developed a numeric method to retrieve their pulse-lengths and chirps,which named as equal-line retrieve method.In comparison with the traditional FROG-CRAB algorithm with central momentum approximation,our model concerns the actual timemomentum distribution in the electron wave-packet,and the retrieval results appear to be much more accurate,indicating it’s well capable for calibrating sub-100 as pulses. |
