Introducing an optimization model for extending the high harmonic spectrum plateau from fluorine molecule

Abstract

A semi-classical optimization model is introduced for controlling the high-order harmonic generation process and extending the cutoff frequency. This method is capable of defining the driving laser shape interact with the F2 molecule for maximizing the cutoff frequency properly. This optimization procedure is evaluated by examining the high harmonic spectrum from the F­2 molecule irradiated by a two-color laser field. High harmonic spectrum is done using time-dependent density functional theory in a three-dimensional space. The results showed that adding two driving laser pulses with optimization could enhance the cutoff frequency by 96% compared to two driving laser pulses without optimization. In addition, this model for the F2 molecule is capable of reducing the output attosecond pulse duration from 200 as not optimized two-color laser to 135 as the optimized two-color laser.

Keywords

• high harmonic generation
• attosecond pulse