Thank you very much for your reply
I am using OptiFDTD v 12.0 Licensed version. My design file (fdt) is attached here.
In my design, I have used 2 observation lines, line 1 (reflection) is placed behind the input field for Reflection and line 2 (Transmission) is on the other side to see the transmission. In the simulation parameters under DFT Spectrum, I write 41 as no of samples, and wavelength range from 0.4 to 0.9.
But in the analyzer under Power Spectrum, when i select observation line 1 (Reflection) i can see the graph but i am not sure is it reflection or not?
In observation line 2 (transmission) i got 2 graphs, one is with absolute value and the other is without absolute value. Can you please tell me what is the mean by absolute value? So among all these 3 graphs which i consider for reflection and transmission?
Hope you got my point.