Attosecond Nonlinear Fourier Transform Molecular Spectroscopy

Abstract

Nonlinear Fourier transform spectroscopy is extended to the attosecond temporal domain and extreme ultraviolet wavelength region to perform two-color two-photon photofragment excitation spectroscopy of molecules and to investigate ultrafast molecular dynamics such as temporal evolution of vibrational and electronic wavepackets. Molecular nonlinear responses are encoded in the fringe-resolved autocorrelation trace of an attosecond pulse train through non-sequential two-photon processes. Femtosecond vibrational motion of molecules can be traced in real-time through sequential two-photon processes. By introducing a velocity map imaging spectrometer, momentum image of photofragment ions and/or photoelectrons can be measured to investigate coupled electron-nuclear dynamics from femtosecond to attosecond.