Phase-matching successive high-order harmonic generation in a hollow fiber

摘要

High-order harmonic generation in hollow fibers through step processes involving lower order intermediate nonlinear processes is considered. Analysis of equations derived for the amplitudes of high-order harmonics produced through direct and step processes with allowance for the dispersion of waveguide modes of a hollow fiber shows that, with an appropriate choice of the sort and the pressure of the gas filling the fiber, parameters of the fiber, the wavelength of pump radiation, and the waveguide modes, phase-matching conditions can be simultaneously satisfied for both steps of a successive high-order harmonic-generation process involving third-harmonic generation at the first step. Phase-matching conditions of this type are determined for ninth-harmonic generation in a hollow fiber filled with helium. [References: 22]