title: Optical saturation in fluorescence correlation spectroscopy under continuous-wave and pulsed excitation.
abstract: A detailed theoretical and experimental study of the dependence of fluorescence correlation measurements on optical excitation power due to optical saturation effects is presented. It is shown that the sensitivity of a fluorescence correlation measurement on excitation power becomes increasingly stronger for decreasing excitation power. This makes exact measurements or diffusion coefficients with fluorescence correlation spectroscopy rather difficult. A strong difference of this behavior for continuous-wave and pulsed excitation is found.
authors.affiliation: Institute for Biological Information Processing 1, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Gregor
authors.forename: Digambara
authors.initials: D
authors.lastname: Patra
authors.forename: Jörg
authors.initials: J
authors.lastname: Enderlein