I would like to couple light vertically to a grating, using a waveguide. I am taking the example from the phas shifted bragg grating.
My question is can I modify the ports in the above example to as I shown in the attached figure. I want to input light from the waveguide above the grating. Is it correct physics?
Because I read about coupling of evanscent waves in the following example and it followed a very complex treatment.
Please let me know.