title: Ultrashort optical-vortex pulse generation in few-cycle regime.
abstract: We generated a 2.3-cycle, 5.9-fs, 56-μJ ultrashort optical-vortex pulse (ranging from ~650 to ~950 nm) in few-cycle regime, by optical parametric amplification. It was performed even by using passive elements (a pair of prisms and chirped mirrors) for chirp compensation. Spectrally-resolved interferograms and intensity profiles showed that the obtained pulses have no spatial or topological-charge dispersion during the amplification process. To the best of our knowledge, it is the first generation of optical-vortex pulses in few-cycle regime. They can be powerful tools for ultrabroadband and/or ultrafast spectroscopy and experiments of high-intensity field physics.
authors.affiliation: Department of Applied Physics, Hokkaido University, Kita-ku, Sapporo, Japan. k-yamane@eng.hokudai.ac.jp
authors.forename: Keisaku
authors.initials: K
authors.lastname: Yamane
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Toda
authors.forename: Ryuji
authors.initials: R
authors.lastname: Morita
mesh_terms: D000669:Amplifiers, Electronic; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D012031:Refractometry / Q000295:instrumentation*