Autocorrelation Measurement of Attosecond Pulses Based on Two-Photon Double Ionization

TL;DR

This paper demonstrates a theoretical method for characterizing intense attosecond pulses using two-photon double ionization autocorrelation, enabling pulse measurement and parameter extraction.

Contribution

It introduces a novel autocorrelation approach based on TPDI to measure and analyze intense attosecond pulses.

Findings

Autocorrelation curve relates FWHM of pulses to TPDI probability.

Method can extract pulse center frequency and FWHM from fitting.

Peak intensity required for experiments is estimated around 10^{16} W/cm^2.

Abstract

Autocorrelation measurement is theoretically demonstrated to characterize attosecond pulses by studying the two-photon double ionization (TPDI) process. An interferometric autocorrelation curve is presented in the change of TPDI probability with the time delay between two identical attosecond pulses, and its full width at half maximum (FWHM) $\tau_{e}$ has a relationship $\tau_{e}=1.77\tau+15$ with the FWHM $\tau$ of the attosecond pulse. The curve is also decoded to obtain the center frequency and FWHM of the attosecond pulse by fitting. In addition, the required peak intensity of the attosecond pulse is estimated to be on the order of $10^{16}\,\rm{Wcm^{-2}}$ in autocorrelation experiments. The findings pave the way for autocorrelation measurement of intense isolated attosecond pulses.