Nonlinear fourier-transform spectroscopy of D2 using high-order harmonic radiation

Abstract

High-order harmonic radiation is available to investigate ultrafast nonlinear optical phenomena, such as two-photon absorption process, in the vacuum and extreme ultraviolet wavelength region.We have determined the sequential twophoton dissociative ionization pathways of D2 with the simultaneous irradiation of multiple order harmonics of a Ti:sapphire laser in the visible-vacuum ultraviolet region with the aid of both an interferometric autocorrelation measurement and a Fourier-transform spectroscopy. By analyzing the interferometric autocorrelation signals appearing in the measured momentum distribution of D+, we were able to decompose the measured momentum distribution into three momentum distribution images representing the three distinct dissociation pathways, which are sequentially two-photon excitation processes of D2. D+2 is prepared in the electronic ground state of D+2 , and then excited to the first excited state, leading to the dissociation into D+ and D. © Springer-Verlag Berlin Heidelberg 2012.