The simplest route to generating a train of attosecond pulses

摘要

We report on two novel routes to generating a train of attosecond pulses from a broad discrete spectrum in the near-infrared–visible–ultraviolet range.One extends an integer-temporal-Talbot(ITT)concept to include high-order spectral dispersions and generates a pulse train that completely satisfies the transform-limited condition.The other numerically explores the optimum conditions under which we can obtain an attosecond pulse train that approximately satisfies the transform-limited condition.The second method is more practical than the first.Either of these methods is extremely simple and robust;we need only to place a few thin dispersive materials in the optical path and to adjust their thicknesses without spatially dispersing the frequency components.We numerically demonstrate the generation of a train of attosecond pulses with a transform-limited pulse duration of 728 as and a repetition period of 8.03 fs in gaseous parahydrogen.