Abstract

Absorption in optical materials is often approximated with a Lorentzian 1/(1+ω²) lineshape. The Lorenz oscillators, however, represent a simplified dispersion mechanism, where all the individual microscopic oscillators are coherent, and the lineshape broadening is homogeneous (given with constant Γ). This type of approximation is often valid for transitions in crystalline solids. However, in the presence of amorphous materials, random nanostructures, disorder, or defects in the materials, inhomogeneous broadening plays a significant role in impacting the lineshape, which is classically approximated with the Gaussian (Maxwellian velocity statistics), exp[–ω²ln2] or Voight (convolution of Lorentzian and Gaussian) profiles.

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