title: Anomalous oscillations in the spectra of light backscattered by inhomogeneous microparticles.
abstract: We report anomalous oscillatory features in the spectra of cross-polarized backscattered light from inhomogeneous dielectric microparticles. Numerical experiments based on the finite-difference-time-domain method demonstrate that cross-polarized backscattered spectra exhibit oscillation frequencies with two a priori surprising features. First, the oscillation frequencies decrease as the correlation length (Lc) of the particle's refractive index increases. Second, high-frequency oscillations exist even for Lc much smaller than the optical wavelength. These findings are exactly opposite to what is observed in co-polarized backscattering spectra, and are not expected from conventional optical scattering theory. We explain this anomalous behavior by examining the path-length distributions of the backscattered photons in the cross polarization.
authors.affiliation: Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Xu
authors.initials: X
authors.lastname: Li
authors.forename: Allen
authors.initials: A
authors.lastname: Taflove
authors.forename: Vadim
authors.initials: V
authors.lastname: Backman
mesh_terms: D016880:Anisotropy; D008027:Light; D013058:Mass Spectrometry; D008433:Mathematics; D008859:Microscopy, Polarization; D008962:Models, Theoretical; D053758:Nanoparticles / Q000032:analysis*; D017785:Photons; D012031:Refractometry; D012542:Scattering, Radiation; D013269:Stochastic Processes