Generation of ultrafast coherent soft X-ray radiation by high - order harmonics and its applications

Abstract

Ultrashort high‐intensity laser technology has progressed tremendously over the last 10 years and enabled us to produce an optical field much stronger than a coulomb field in atoms. The extremely nonlinear response of materials caused by such a strong optical field makes it possible to realize a compact laboratory source of coherent ultrafast extreme ultraviolet and soft X‐ray (XUV) radiation by high‐order harmonic generation. This unique short‐wavelength source provides a possible route for “Attosecond science:generation, measurement and application" and “Nonlinear optics in the soft X‐ray regime", which have not been explored yet. Recent progress in this rapidly growing field is reviewed, including our efforts on the generation and application of high‐intensity XUV radiation.