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Mohammadreza Mohebifar

Mohammadreza Mohebifar

Academic rank: Associate Professor
ORCID:
Education: PhD.
ScopusId:
HIndex:
Faculty: science
Address:
Phone: +988132355404

Research

Title
Angular distribution of laser-induced fluorescence emission of active dyes in scattering media
Type
JournalPaper
Keywords
laser-induced fluorescence, optical scattering media, Angular distribution, Rd6G
Year
2018
Journal APPLIED OPTICS
DOI
Researchers Mohammadreza Mohebifar

Abstract

Angular dependence of the intensity and the emissive wavelength of the laser-induced fluorescence emission in hybrid media (fluorophores  nanoparticles) are investigated using various TiO2 densities as guest nanoscatterers in the ethanolic solutions of the host Rd6G and coumarin 4 (C4) molecules. It is shown that the intensity of the scattered photons varies in terms of the detection angle. When the nanoscatterer density increases at a certain excitation energy, the angular anisotropy enhances. While the emissive wavelength exhibits the spectral shift in terms of the angular variation for Rd6G fluorophores, it remains invariant for C4-based suspension. In the former case, the emissive wavelength undergoes a spectral shift in terms of angular variation. Several factors such as the optical path length in the scattering media, the excitation volume, and the re-absorption events of the fluorescence emissions by the non-excited molecules strongly affect the spectral features. In fact, the density of the scatterers, the dye concentration, and the interplay between Stokes shift rate and the overlapping between absorption/ emission spectra of the given fluorophores are taken into account as the major parameters to form the angular distribution.