Abstract

Ultrafast laser based EUV sources are suitable for studying ultrafast dynamics in materials exposed to ultrashort laser pulses. Among them, high-order harmonics are the best candidates for probing the dynamics that occur in the attosecond to femtosecond region [1, 2]. It is known that the carrier-envelope phase (CEP) of a driving laser affects the emission spectra in the EUV region [3–5]. We investigated the dependence of EUV emissions not only on the CEP but also on the energy and the duration of the driving laser pulse. We measured the emission spectra in a broader wavelength region than that previously reported [3–5]. As a result, we found that these spectra can be divided into three regions that show different degrees of driving laser pulse dependence on the CEP.

© 2009 IEEE