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Gans Theory
Gans theory or Mie-Gans theory is the extension of Mie theory for the case of spheroidal particles. It gives the scattering characteristics of both Oblate spheroid, oblate and prolate spheroidal particles much smaller than the excitation wavelength. Since it is a solution of the Maxwell equations it should technically not be called a theory. The theory is named after Richard Gans who first published the solution for gold particles in 1912 in an article entitled "Über die Form ultramikroskopischer Goldteilchen". A subsequent article in 1915 discussed the case of silver particles. In Gans theory, the absorption (electromagnetic radiation), absorption is only dependent on the aspect ratio of the particles and not on the absolute dimensions. This dependence is introduced through so called polarization- or shape factors related to the three dimensions of the particle. For the case of spheroids, this reduces to only two different factors since the particle is rotational symmetry, rotatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mie Theory
In electromagnetism, the Mie solution to Maxwell's equations (also known as the Lorenz–Mie solution, the Lorenz–Mie–Debye solution or Mie scattering) describes the scattering of an electromagnetic plane wave by a homogeneous sphere. The solution takes the form of an infinite series of Vector spherical harmonics, spherical multipole partial waves. It is named after German physicist Gustav Mie. The term ''Mie solution'' is also used for solutions of Maxwell's equations for scattering by stratified spheres or by infinite cylinders, or other geometries where one can write separation of variables, separate equations for the radial and angular dependence of solutions. The term ''Mie theory'' is sometimes used for this collection of solutions and methods; it does not refer to an independent physical theory or law. More broadly, the "Mie scattering" formulas are most useful in situations where the size of the scattering particles is comparable to the wavelength of the light, rather ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
