Thank you for your reply and your patience. It took a while to implement your advice, as I had some license issues. After following your question, I found that I can edit the parameters in unit_cell_fdtd, but still have a couple of issues.
In "unit_cell_fdtd", I noticed in the sweep that E would get the information from s_params. After changing the wavelength in s_params and clicking "ok", I noticed that the matlab file "EH_and_phase_vs_radius_fdtd" would print the wavelength as 6.6e-7. I also changed the source and reran the simulation, but the wavelength remains 6.6e-7. I will delete all the matlab files and run "unit_cell_fdtd", but I noticed the newly generated matlab file would have wavelength = 6.6e-7. Is there something else I am supposed to change so the wavelength in this file is also changed? I would just edit line 49, but I'm worried I may be incorrectly editing some parameters.
My next question regards "unit_cell". I will not run "unit_cell.lsf" without editing it, and I notice "unit_cell" will only run up to 83, giving an error "... in 3D interp, if the first argument has a size of NxMxP, the fourth argument must have length P". Did you also get this error? As this is an example, shouldn't I just be able to run this code?
Thank you so much for your response.