I have been attempting to calculate the scattering and absorption spectra for a 75 nm diameter Ag sphere using FDTD-solutions. There must be an error in the way I am setting up my .fsp files (included below) because the spectra I get have strong oscillations/structure:
Absorption Cross Section:
Scattering Cross Section:
These oscillations are absent in the spectra I get using Mie theory (JC dielectric function for Ag used in both cases).
I’ve followed the suggestions given in previous posts to solve similar issues (e.g. How to set the parameters to simulate the scattering or absorption of a gold nanorod) but my problem has persisted. For example, I’ve ensured that the auto-shut-off is reached in the attached simulation, and have even lowered the shut-off to 1e-6. I’ve also varied the mesh size in the override region from 2.0 - 0.5 nm with little to no improvement observed.
Any comments/suggestions would be greatly appreciated.