Materials

Dielectric functions

CoupledDipole.epsilon_AgFunction
epsilon_Ag(λ::Real)

Drude model for the dielectric function of silver in the visible region

  • λ: wavelength in nm

Examples

julia> round(epsilon_Ag(632.8), digits=5)
-16.11377 + 0.74871im
source
CoupledDipole.epsilon_AuFunction
epsilon_Au(λ::Real)

Extended Drude model for the dielectric function of gold in the visible region

  • λ: wavelength in nm

Examples

julia>  round(epsilon_Au(632.8), digits=5)
-11.40185 + 1.18679im
source

Particle polarisabilities

CoupledDipole.depolarisation_spheroidFunction
depolarisation_spheroid(a, b, c)

Depolarisation factor of a spheroid

  • a: semi-axis along x and y
  • b: semi-axis along x and y (unused)
  • c: semi-axis along z

Examples

julia> round.(depolarisation_spheroid(1, 1, 1.5), digits=5)
3-element SVector{3, Float64} with indices SOneTo(3):
 0.38351
 0.38351
 0.23298
source
CoupledDipole.alpha_kuwataFunction
alpha_kuwata(λ, ε, ε_m, Size)

Principal polarisability components of a spheroidal particle

  • λ: wavelength
  • ε: complex dielectric function
  • ε_m: dielectric function of surrounding medium
  • Size: SVector with 3 semi-axes of the spheroid

Examples

julia> alpha_kuwata(500, -10+1im, SVector(30, 30, 50), 1.33^2)
3-element SVector{3, ComplexF64} with indices SOneTo(3):
  77076.04648078184 + 26235.664281642235im
  77076.04648078184 + 26235.664281642235im
 -98187.15974124733 + 205835.30299929058im
source

Molecular polarisabilities

CoupledDipole.lorentzianFunction
lorentzian(λ::Real, α_k::Real, λ_k::Real, µ_k::Real)

Complex Lorentz function, to describe polarisabilities

  • λ: wavelength in nm
  • α_k: oscillator strength in S.I. units
  • λ_k: oscillator wavelength in nm
  • µ_k: damping in S.I. units

Examples

julia> round(lorentzian(632.8)*1e39, digits=5)
6.58095 + 1.35961im
source
CoupledDipole.alpha_bareFunction
alpha_bare(λ::T, α_∞::T, α_k::Array{T}, λ_k::Array{T}, µ_k::Array{T}) where T <: Real

Complex scalar polarisability, as sum of lorentz oscillators

  • λ: wavelength in nm
  • α_k: oscillator strength(s) in S.I. units
  • λ_k: oscillator wavelength(s) in nm
  • µ_k: damping(s) in S.I. units

Default values mimic the main resonance of Rhodamine 700

Examples

julia> round(alpha_bare(632.8), digits=5)
0.14543 + 0.01222im
source
CoupledDipole.alpha_embedFunction
alpha_embed(α::Complex{T}, medium::T) where T <: Real

Effective point polarisability in medium, rescaled by local field correction

  • α: bare polarisabilty
  • medium: refractive index of embedding medium

Default values mimic the main resonance of Rhodamine 700

Examples

julia> round(alpha_embed(alpha_bare(632.8)), digits=5)
0.12976 + 0.0109im
source
CoupledDipole.alpha_scaleFunction
alpha_scale(alpha, sizes::SVector{3})

Principal polarisability components of a particle, rescaled along each principal axis

  • α: scalar polarisabilty
  • sizes: 3-vector to scale along each principal axis
source