Hello I am using Rsoft- Beamprop program to do some simulations on a multilayer waveguide. Can anyone please help me to interpret the graph (simulation results) attached. Explanation of the graphs :- I have done some calculations to find the output power (wavelength = 633micrometer) through a waveguide of silicon dioxide- core- air structure. I have done 3 calculations with various core thickness and have obtained the 3 graphs (please see the attached file), as shown. But how do I interpret these results? All these three graphs represents the propagation of light ( wavelength = 633micrometer,and width= 10 micrometer ) with various core thickness. Except the thickness of the core, all the parameters are same for all the three graphs. The substrate is silicon, first cladding is silicon dioxide, core is SU-8 photoresist, and on the top it is the air. Can you please help me to explain the results. In the first graph I understood that there is no propagation of light though the waveguide (power=0). But how about the 2nd and 3rd graphs? How to interpret the difference in the shape of the launch power and Waveguide power ?