Dynamics of lithium atom photoionization by ultrashort photo-pulse

Joint Event on 6^th International Conference on Photonics & 7^th International Conference on Laser Optics

July 31- August 02, 2017 Milan, Italy

A A Mityureva, A S Kozhina and V V Smirnov

Saint Petersburg State University, Russia

Posters & Accepted Abstracts: J Laser Opt Photonics

Abstract :

The process of photoionization of the lithium atom in ultrashort laser field was considered. The trajectory-based method for evaluating transition probabilities developed is in the core of our computations. The method is nonperturbative and considers all orders of multiphoton and recollision processes. The photoionization probabilities for several ionization multiplicities were calculated in a wide range of field frequencies and intensities. The frequency range corresponded to photon energies of 8 eV - 8 KeV and wavelengths of 1-1500 �?�?. The range of the field magnitudes corresponded to energy flux densities of 106-1025 W/cm2. This are unique capabilities compared to the other methods. We employ a relativistic Hamiltonâ�?�?s function. We consider a plane-wave photo-pulse with linear polarization and a Gaussian modulation. Atomic units are used if not stated otherwise. The results of calculations of the lithium atom photoionization probability temporal dependence are shown in Fig. 1. Lines 1-4 correspond to the total, single, double and triple ionization respectively. The magnitude of the field is represented by the dimensionless Faisal parameter Ï�?=eA/p0c (where A is vector potential amplitude and p0=�?§/a0). If Ï�?Ï�?>> 1 then Ï�?~1/�?³, where �?³ is the adiabatic Keldysh parameter. The range of Faisal parameter Ï�?<<1 corresponds to a weak field, Ï�?-1 corresponds to an intermediate field, 1<Ï�?