I’m trying to simulate a directional coupler example or MMI model (as indicated in OptiBPM Tech Background and tutorials file) it works properly, but when I change the refractive index of the wave guide to be less than that of the surrounding (cladding) it doesn’t work and I get error “2D simulator application stops working”
who can I use a refractive index for the guide less than that of the surrounding?
the file is attached, thanks in advance
