Pole expansion of the Lorenz-Mie coefficients
نویسنده
چکیده
A spectral approach to the Lorenz-Mie problem was adopted to obtain a pole expansion of the Lorenz-Mie coefficients in the complex variable z = 4π/(n − 1), where n is the dielectric permittivity of the scatterer. In the absence of magnetic properties (which is assumed), n is the refractive index of the scatterer. It is shown that the Lorenz-Mie coefficients are meromorphic functions of z with simple poles. The poles and the residues are functions of the size parameter x = ka = 2πa/λ and of the order of the Lorenz-Mie coefficient, l, but are independent of the material properties. This leads to a numerically efficient representation of the Lorenz-Mie coefficients.
منابع مشابه
Fundamentals of negative refractive index optical trapping: forces and radiation pressures exerted by focused Gaussian beams using the generalized Lorenz-Mie theory
Based on the generalized Lorenz-Mie theory (GLMT), this paper reveals, for the first time in the literature, the principal characteristics of the optical forces and radiation pressure cross-sections exerted on homogeneous, linear, isotropic and spherical hypothetical negative refractive index (NRI) particles under the influence of focused Gaussian beams in the Mie regime. Starting with ray opti...
متن کاملMie scattering by a uniaxial anisotropic sphere.
The field solution to the electromagnetic scattering of a plane wave by a uniaxial anisotropic sphere is obtained in terms of a spherical vector wave function expansion form. Using the source-free Maxwell's equations for uniaxial anisotropic media and making the Fourier transform of the field quantities, the electromagnetic fields in the spectral domain in uniaxial anisotropic media are assumed...
متن کاملCalculation of the radiation trapping force for laser tweezers by use of generalized Lorenz-Mie theory. I. Localized model description of an on-axis tightly focused laser beam with spherical aberration.
Calculation of the radiation trapping force in laser tweezers by use of generalized Lorenz-Mie theory requires knowledge of the shape coefficients of the incident laser beam. The localized version of these coefficients has been developed and justified only for a moderately focused Gaussian beam polarized in the x direction and traveling in the positive z direction. Here the localized model is e...
متن کاملLight scattering resonances in small particles with electric and magnetic properties.
Lorenz-Mie resonances produced by small spheres are analyzed as a function of their size and optical properties (epsi > or < 0, mu > or < 0). New generalized (mu not equal to 1) approximate and compact expressions of the first four Lorenz-Mie coefficients (a1, b1, a2, and b2) are calculated. With these expressions and for small particles with various values of epsi and mu, the extinction cross ...
متن کاملRobustness of Lorenz-Mie microscopy against defects in illumination.
Lorenz-Mie analysis of colloidal spheres' holograms has been reported to achieve remarkable resolution not only for the spheres' three-dimensional positions, but also for their sizes and refractive indexes. Here we apply numerical modeling to establish limits on the instrumental resolution for tracking and characterizing individual colloidal spheres with Lorenz-Mie microscopy.
متن کامل