title: Noncollinear phase matching in fluorescence upconversion.
abstract: We investigate noncollinear sum-frequency generation in a time-resolved fluorescence upconversion experiment to eliminate group-velocity mismatch (GVM), a major mechanism that deteriorates time resolution. The noncollinear geometry inherently causes phase-front mismatch (PFM) that also spoils time resolution. The effects of GVM and PFM on the time resolution are studied by numerical calculations and experiments. Based on the investigation, a fluorescence upconversion apparatus with time resolution better than 45 fs (FWHM) is demonstrated.
authors.affiliation: Division of Molecular and Life Sciences, Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, South Korea.
authors.forename: Hanju
authors.initials: H
authors.lastname: Rhee
authors.forename: Taiha
authors.initials: T
authors.lastname: Joo