Synthesis of a beat-wave pulse train with increasing pulse separation for quasi-phase-matched high-harmonic generation

摘要

A beat-wave pulse train is synthesized from a two-color Ti:sapphire amplifier system with a split-grating compressor. Pulse separation from several tens femtoseconds to more than one hundred femtoseconds can be controlled by the frequency difference of the two input pulses and the increase of separation by their chirps. The pulse train can be used for quasi-phase-matching of high-harmonic generation. Simulations show that efficient harmonic generation at the water window can be achieved by colliding the harmonic-driving pulse with an optimized beat-wave pulse train constructed in this work in an ionized neon jet.