# Resonance Expansion¶

The geometry is as in the parent example but the resonance mode solver is used to compute the eigenmodes near the resonant frequency.

Note

The Drude material model is fully taken into account by the resonance solver.

Resonance expansion

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: