How do we model unpolarized light (incident radiation) in FDTD Solutions? We wish to investigates its interaction with a plasmonic solar cell?
One option will be to vary the polarisation of light and calculate for different polarisations. Then you can average out to yield the enhancement factor for unpolarised light. With this approach you can get information on the polarisation dependence of your plasmonic solar cell geometry.
In order to model unpolarized light, you need to run 2 simulations with orthogonally polarized sources and then add incoherently the results of each simulations, as shown here: https://kb.lumerical.com/en/index.html?ref_sim_obj_fdtd_coherence_unpolarized_beam.html.