Hello, Everyone!
Currently I am trying to calculate a band diagram of a lossy photonic crystal. To do this I use the example posted on comsol site that is true for a conservative case. If one consider some structure with a complex refracive index possesed large enough imaginary part the band diagram will not be calculated. Solver throws a convergence error. But, nevertheless, comsol allows to calculate distributions of mode that corresponds complex eigenfrequencies for different values of wave vectors even in this non-conservative case. So the question: is there any option that can help to calculate the band diagram or tune solver in such a way to skip complex eigenvalues at least.