Generation of intense continuum extreme-ultraviolet radiation by many-cycle laser fields

Abstract

Continuing efforts in ultrashort pulse engineering have recently led to the breakthroughs of the generation of attosecond (10 18 s) pulse trains and isolated pulses. Although trains of multiple pulses can be generated through the interaction of many-optical-cycle pulses with gasesa process that has led to intense extreme-ultraviolet emissionthe generation of isolated high-intensity pulses, which requires few-cycle driving pulses, remains a challenge. Here, we report a vital step towards the generation of such pulses, the production of broad continuum extreme-ultraviolet emission using a high-intensity, many-cycle, infrared pulsed laser, through the interferometric modulation of the ellipticity of 50-fs-long driving pulses. The increasing availability of high-power many-cycle lasers and their potential use in the construction of intense attosecond radiationwith either gas or solid-surface targetsoffer exciting opportunities for multiphoton extreme-ultraviolet-pump-extreme- ultraviolet-probe studies of laser-matter and laser-plasma interactions.