Pulse Characterization via Two-Photon Auto- and Cross-Correlation Signals

Characterization of ultrashort vacuum and deep ultraviolet is crucial for applications in spectroscopic and dynamical imaging of atoms, molecules, and materials. We present an extension of the autocorrelation technique proposed in [1] to include the possibility of linear chirp and cross-correlation photoionization spectra.

In the method, analytic solutions for two-photon ionization of atoms by Gaussian pulses are used to characterize the pulse as a superpositions of multiple Gaussians at multi-color central frequencies. This approach allows one to use two-photon auto- and cross-correlation signals to characterize ultrashort pulses and pulse trains, i.e. the time-dependent amplitude, phase, and chirp variation of the electric field. This method is demonstrated with vacuum and deep ultraviolet pulses and pulse trains obtained from numerical simulations of macroscopic high harmonic spectra [2].

[1] S. Walker, R. Reiff, A. Jaron-Becker, and A. Becker. Characterization of vacuum and deep ultraviolet pulses via two-photon autocorrelation signals. Opt. Lett., 46(13):3083-3086, Jul 2021.

[2] R. Reiff, J. Venzke, A. Jaron-Becker, and A. Becker. Intereference effects in harmonic generation induced by focal phase distribution. OSA Continuum, 4(7):1897-1906, Jul 2021