Hello, 

I have reproduced some simple simulation with gratings using this software and all of them gave the exact answer I wanted. But when I am trying to do a simulation which includes a layer of TiO2 over the grating the resonance occurs at a different wavelength. I have reproduced the results with another software, so I know the values are correct. I really wanted to know if there is any method to include a thin layer of TiO2 on the sides of the gratings. It will be very helpful if anyone can help me out