title: Single-shot spectra of temporally selected micropulses from a mid-infrared free-electron laser by upconversion.
abstract: We demonstrate the measurement of single-shot spectra of temporally selected micropulses from a mid-infrared free-electron laser (FEL) by upconversion. We achieve the upconversion of FEL pulses at 11 μm using externally synchronized Nd:YAG or microchip laser pulses at 1064 nm to produce sum-frequency mixing signals at 970 nm, which are detected by a compact CCD spectrometer without an intensifier. Our experimental system is very cost-effective, and allows us to obtain the laser spectra of selected micropulses at any temporal position within a single macropulse from an oscillator-type FEL.
authors.affiliation: Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Wang
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakajima
authors.forename: Heishun
authors.initials: H
authors.lastname: Zen
authors.forename: Toshiteru
authors.initials: T
authors.lastname: Kii
authors.forename: Hideaki
authors.initials: H
authors.lastname: Ohgaki