Titanium diffused lithium niobate waveguide simulation

I’m trying to simulation some Ti diffused lithium niobate waveguides in Mode/FDTD Solutions. These waveguides have “diffused” refractive index distributions and therefore cannot be modeled by rectangular shapes or any other standard shapes.
Does anyone have experience modeling such waveguides? I know some other software have built-in index distributions for these waveguides, but not sure if Lumerical can do so as well.
Thanks in advance!


There are several Import options available in FDTD and MODE Solutions. Particularly, I think the spatial nk material import method may be useful because you can define your own spatial nk for import. It might be able to take care of the diffused refractive index you are referring to.

Thanks kchow, I’ll take a look at this method.