I found the absorption and scattering cross section of nanoantenna using TFSF source and total, scattering power box. I also want to calculate reflectance and transmittance, so I used plane wave source with periodic boundary condition in x and y direction. But am getting strange result. I herewith attached my simulation file for calculating absorption cross section and also file for calculating reflectance.
I kindly request to solve this problem.
The below images shows my result for cross sections and reflectance.