title: Spatial distribution of two-photon-excited fluorescence in scattering media.
abstract: Spatial distribution of two-photon-excited fluorescence (TPF) for dye beneath the surface of a highly scattering medium was investigated with picosecond laser pulses at 1064 nm. The active scattering media consisted of a suspension of polystyrene particles in a solution of Rhodamine 590 Tetrafluoroborate dye. With the increase of scattering strength of the medium, the location of the maximum TPF intensity was found to move closer to the surface away from the focal region; the intensity of TPF was not confined to the focal region as in the case of nonscattering medium but was more evenly distributed. The spatial resolution of nonlinear optical microscopy for probing a scattering medium is degraded. Taking into account the scattering of the medium qualitatively explains the observed TPF spatial distribution.
authors.affiliation: Department of Physics, Institute for Ultrafast Spectroscopy and Lasers, New York State Center for Advanced Technology for Ultrafast Photonic Materials and Applications, The City College and the Graduate School, City University of New York, New York, New York 10031, USA.
authors.forename: J
authors.initials: J
authors.lastname: Ying
authors.forename: F
authors.initials: F
authors.lastname: Liu
authors.forename: R R
authors.initials: RR
authors.lastname: Alfano