Attosecond cross correlation technique

A technique for the measurement of attosecond, extreme-ultraviolet pulses i s proposed and theoretically analyzed that is based on cross correlation of the attosecond pulse with a strong laser pulse in a gas target. Pulse dura tions on the time scale of a fraction of the optical period can be resolved . The method is linear in the extreme-ultraviolet intensity, which ensures high efficiency and applicability for wavelengths to below 10 nm.