The geometry is as in the parent example but the resonance mode solver is used to compute the eigenmodes near the resonant frequency.
The Drude material model is fully taken into account by the resonance solver.
The computed resonances can be used to approximate a scattering problem as defined in parent example by an expansion into resonance modes, see example drivers in the sub-folder
data_analysis. Running a wavelength scan for the resonance expansion approximation yields nearly identically decay rates as for the scattering problem: