Extended model for optimizing high-order harmonic generation in absorbing gases

Abstract We report on an extended version of the one-dimensional model proposed by Constant et al (1999 Phys. Rev. Lett. 82 1668) to study phase matching high-order harmonic generation in absorbing and dispersive medium. The model—expanded from zeroth first order—can be used with media having a pressure profile varying linearly propagation length. Based new formulas, importance medium that ends abruptly steep gradient for achieving high flux is highlighted. In addition further rule-of-thumb guidelines harmonic-flux optimization, it shown increase beginning increases flux, while also decreases required length reach absorption-limited maximum.