title: Two-dimensional collision of probe photons with relativistic ionization fronts.
abstract: The collision of a probe laser pulse with a relativistic ionization front is analyzed via two-dimensional ray-tracing theory and simulations. It is shown that collisions in higher dimensions lead to new regimes for the frequency upshift of the probe photons; the frequency upshift can be considerably higher for particular collision angles that maximize the interaction length with the ionization front gradient. Finite ionization fronts also lead to angle-dependent frequency upshifts, thus acting as diffraction gratings.
authors.affiliation: GoLP/Centro de Física de Plasmas, Instituto Superior Técnico, 1049-001 Lisboa, Portugal. jmdias@alfa.ist.utl.pt
authors.forename: J M
authors.initials: JM
authors.lastname: Dias
authors.forename: N C
authors.initials: NC
authors.lastname: Lopes
authors.forename: L O
authors.initials: LO
authors.lastname: Silva
authors.forename: G
authors.initials: G
authors.lastname: Figueira
authors.forename: J T
authors.initials: JT
authors.lastname: Mendonça