I am studying the reflectance of a periodic structure (silver cylinders raised above a gold substrate). The structure is very closed pack (the distance between cylinders is 5 nm) and my simulation wavelength range is (300 – 900 nm). To simulate such a structure, the length and width of FDTD simulation region
should be 65 nm (a 60 nm diameter cylinder with 5 nm distance with the adjacent cylinder) and I am using periodic boundary conditions.
• My main concern is the minimum FDTD simulation box size that gives reliable results knowing that my simulation range is (300 – 900 nm).
• Based on mesh refinement options I am using “Conformal variant 1” to account for the metal-metal interface. Is that the right choice?
• Could you kindly check the simulation setup specifically source distance from the structure and the monitor distance from the source (which is used for measuring reflectance)
Please find the simulation file and the structure setup attached.