iam trying to simulate evanescent coupling between two glass waveguides which are based on an ion diffusion process and have a spatially varying refractive index profile (similar to here)
in contrast to the example in the application gallery the waveguides in glass are pretty wide and have a mode field diamater of about 10µm due to the low change in refractive index.
the estimated coupling length for a pitch between those waveguides (center to center) of 18µm is about ~3mm.
the problem now is that the 2 waveguide objects are overlaid when i place them that close and it seems that in the FDE simulation only the superficial waveguide is considered.
as a workaround i could merge the two profiles of the waveguides numerically into 1 profile and use this in my simulation but i’d like to avoid this.
any idea/hint is much appreciated!
glass_wg_coupler.lms (499.4 KB)