Delay control in laser-assisted photoionization of water molecules by attopulses

DIEGO I. R. BOLL; OMAR A. FOJÓN; LARA MARTINI

San Francisco

Conferencia; SPIE Photonics West 2020; 2020

SPIE The international society for optics and photonics

The knowledge of the ionization of water is essential in dierent elds such as Biology and Atomic Physics. Basic reactions involving this molecule are crucial to understand the interaction between radiation and the biological tissue because living cells are composed mostly by water. Therefore, we study theoretically the laser-assisted photoionization of water molecules by attopulses in the streaking regime by means of a Coulomb-Volkov model. We analyze reactions initiated by an extreme ultraviolet single attosecond pulse assisted by a near-infrared laser. The initial molecular wavefunctions are described by using the Moccia´s monocentric wavefunctions whereas the final state wavefunctions are given by the separable Coulomb-Volkov type wavefunctions. We obtain analytical expressions for the observables of interest. We calculate photoelectron spectra as a function of the delay  between the attopulse and the assistant laser eld for water molecules. Several polarization congurations of pulses and assistant laser are considered. Particularly, we focus on the conditions where asymmetries are generated in the observables and we examine those under which these asymmetries could be enhanced and/or diminished leading to a directional selectivity of the photoelectron emission. Consequently, we hope our work promotes progress on the control of the chemical reactivity of water as this could be useful in many domains of radiobiology and medical physics. Finally, we expect these studies contribute to the improvement of attopulses and assistant laser technologies as well as to the development of new polarization and delay control experiments.