title: Below gap optical absorption in GaAs driven by intense, single-cycle coherent transition radiation.
abstract: Single-cycle terahertz fields generated by coherent transition radiation from a relativistic electron beam are used to study the high field optical response of single crystal GaAs. Large amplitude changes in the sub-band-gap optical absorption are induced and probed dynamically by measuring the absorption of a broad-band optical beam generated by transition radiation from the same electron bunch, providing an absolutely synchronized pump and probe geometry. This modification of the optical properties is consistent with strong-field-induced electroabsorption. These processes are pertinent to a wide range of nonlinear terahertz-driven light-matter interactions anticipated at accelerator-based sources.
authors.forename: J
authors.initials: J
authors.lastname: Goodfellow
authors.forename: M
authors.initials: M
authors.lastname: Fuchs
authors.forename: D
authors.initials: D
authors.lastname: Daranciang
authors.forename: S
authors.initials: S
authors.lastname: Ghimire
authors.forename: F
authors.initials: F
authors.lastname: Chen
authors.forename: H
authors.initials: H
authors.lastname: Loos
authors.forename: D A
authors.initials: DA
authors.lastname: Reis
authors.forename: A S
authors.initials: AS
authors.lastname: Fisher
authors.forename: A M
authors.initials: AM
authors.lastname: Lindenberg