Linking high-order harmonic generation and radial distribution function in liquids

Studies on high-order harmonic generation (HHG) in nonliquid media driven by ultrafast lasers have made extensive progress. However, the liquid HHG remains in its infancy. Here, the correlation length of liquids is extracted from the radial distribution function, which gives a link to the maximum harmonic photon energy ${\mathrm{\ensuremath{\Omega}}}_{\mathrm{max}}$. The predicted ${\mathrm{\ensuremath{\Omega}}}_{\mathrm{max}}$ agrees with the numerical one- and two-dimensional model simulations and the real experimental measurements. It provides a powerful tool in order to select optimal liquid candidates to achieve higher harmonic photon energy.