title: High-harmonic inverse-free-electron-laser interaction at 800 nm.
abstract: We present the first direct observation of a higher-order inverse-free-electron-laser (IFEL) interaction. Interaction at the fourth, fifth, and sixth harmonics is observed from an IFEL operating at 800 nm. The harmonic spacing, relative harmonic strength, and transverse beam overlap of the interaction are all in good agreement with tracking simulations.
authors.affiliation: Stanford Linear Accelerator Center, Menlo Park, California 94025, USA.
authors.forename: Christopher M S
authors.initials: CM
authors.lastname: Sears
authors.forename: Eric R
authors.initials: ER
authors.lastname: Colby
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Cowan
authors.forename: Robert H
authors.initials: RH
authors.lastname: Siemann
authors.forename: James E
authors.initials: JE
authors.lastname: Spencer
authors.forename: Robert L
authors.initials: RL
authors.lastname: Byer
authors.forename: Tomas
authors.initials: T
authors.lastname: Plettner