Theoretical investigation of resonant nonperturbative high-order harmonic generation in indium vapors

Our study is devoted to finding an explanation of the observed phenomena of resonance enhancement of the single high-order harmonic in indium plasma [Opt. Lett. 31, 1699 (2006)]. Computations were performed on the basis of time-dependent density functional theory (TDDFT). The results of TDDFT calculations of the high-order harmonic generation (HHG) for indium ion were found in good qualitative coincidence with experimental data. This allowed us to introduce a theory of resonant recombination for the HHG and prove it by HHG simulations with specially chirped pulses. It can also be used to predict the most promising targets for resonant HHG and to increase its efficiency by control of the pump radiation's parameters. (C) 2010 Optical Society of America