title: Temporal characterization of mid-IR free-electron-laser pulses by frequency-resolved optical gating.
abstract: We performed what we believe are the first practical full-temporal-characterization measurements of ultrashort pulses from a free-electron laser (FEL). Second-harmonic-generation frequency-resolved optical gating (FROG) was used to measure a train of mid-IR pulses distorted by a saturated water-vapor absorption line and showing free-induction decay. The measured direction of time was unambiguous because of prior knowledge regarding free-induction decay. These measurements require only 10% of the power of the laser beam and demonstrate that FROG can be implemented as a pulse diagnostic simultaneously with other experiments on a FEL.
authors.affiliation: Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Richman
authors.forename: M A
authors.initials: MA
authors.lastname: Krumbügel
authors.forename: R
authors.initials: R
authors.lastname: Trebino