title: Robust determination of the anisotropic polarizability of nanoparticles using coherent confocal microscopy.
abstract: A coherent confocal microscope is proposed as a means to fully characterize the elastic scattering properties of a nanoparticle as a function of wavelength. Using a high numerical aperture lens, two-dimensional scanning, and a simple vector-beam shaper, the rank-2 polarizability tensor is estimated from a single confocal image. A method for computationally efficient data processing is described, and numerical simulations show that this algorithm is robust to noise and uncertainty in the focal plane position. The proposed method is a generalization of techniques that provide an estimate of a limited set of scattering parameters, such as a single orientation angle for rodlike particles. The measurement of the polarizability obviates the need for a priori assumptions about the nanoparticle.
authors.affiliation: The Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. bryn@uiuc.edu
authors.forename: Brynmor J
authors.initials: BJ
authors.lastname: Davis
authors.forename: P Scott
authors.initials: PS
authors.lastname: Carney
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004867:Equipment Design; D005583:Fourier Analysis; D018613:Microscopy, Confocal / Q000379:methods*; D015233:Models, Statistical; D008962:Models, Theoretical; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D055095:Optics and Photonics; D012542:Scattering, Radiation