Coherent Light Sources in the Extreme Ultraviolet, Frequency Combs and Attosecond Pulses

Abstract

Converting laser radiation into coherent extremeultraviolet radiation via high-order harmonic processes allows the creation of extremely broadband spectra with well-behaved phase structure. Such spectra will exhibit attosecond temporal structure – either in the form of an attosecond pulse train or an isolated attosecond pulse. The basic principles of achieving such broad, phase controlled spectra and the two prevalent non-linear media (extended gaseous media and step-like plasma-vacuum interfaces) will be discussed.