title: Ultrafast time-resolved fluorescence by two photon absorption excitation.
abstract: We report a time-resolved fluorescence apparatus utilizing fluorescence upconversion by noncollinear sum frequency generation and two photon absorption as an excitation. Near perfect time-resolution is achieved with 20 fs pulses to give the instrument response of 33 fs (FWHM) over the entire fluorescence wavelength for a 100 microm thick mixing crystal. Through experiments and numerical simulations, it is shown that 40 fs time-resolution can be obtained even for a 580 microm thick mixing crystal at a fluorescence wavelength longer than 500 nm.
authors.affiliation: Department of Chemistry, Pohang University of Science and Technology, Pohang, S. Korea.
authors.forename: Chul Hoon
authors.initials: CH
authors.lastname: Kim
authors.forename: Taiha
authors.initials: T
authors.lastname: Joo
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D008027:Light; D036641:Microscopy, Fluorescence, Multiphoton / Q000295:instrumentation* / Q000379:methods; D008962:Models, Theoretical; D019047:Phantoms, Imaging; D012542:Scattering, Radiation