Circularly Polarized MHOHG with Bichromatic Circularly Polarized Laser Pulses

Circularly polarized MHOHG-Molecular High Order Harmonic Generation is shown to occur efficiently with intense ultrashort bichromatic circularly polarized pulses due to frequent electron-parent -ion recollision with co-or counter-rotating incident circular pulses as predicted in 1995[1]..We show in this context that molecules offer a very robust and efficient frameworkfor the production of circularly polarized harmonics for the generation of single circularly polarized ``attosecond'' pulses.[2].The efficiency of such new MHOHG is shown to depend on the compatibility of the symmetry of the molecular medium with the net electric field generated by the combination of the laser pulses.Using a time-dependent symmetry analysis with concrete examples such as H2$+$ vs H3$+$ we show how all the features(harmonic order and \textasciicircum polarization) of MHOHG can be explained and predicted. [1] T Zuo,AD Bandrauk,J Nonl Opt Phys Mat 4,533-546(1995);AD Bandrau,HZ Lu,Phys Rev A 68,043408(2003) [2] KJ Yuan,AD Bandrauk, Phys Rev Lett 110,023003(2013)