title: Temporal focusing by use of composite X waves.
abstract: It is shown that highly focused pulses can be shaped by exciting a finite aperture with a spread-out pulse train of X waves. The basis of the proposed scheme is that the peaks of X waves, characterized by different apex angles, travel at different velocities. This property allows one to vary the temporal starting points of the initial excitations of a sequence of X waves so that all their peaks meet at a chosen focusing point. It is demonstrated that this simple criterion can be effective in producing a highly focused, composite X-wave pulse that exhibits a slower decay behavior than the individual X-wave components used in synthesizing it.
authors.affiliation: Physics Department, The American University in Cairo, P.O. Box 2511, Cairo 11511, Egypt. sharaawi@aucegypt.edu
authors.forename: Amr M
authors.initials: AM
authors.lastname: Shaarawi
authors.forename: Ioannis M
authors.initials: IM
authors.lastname: Besieris
authors.forename: Tarek M
authors.initials: TM
authors.lastname: Said