The RPS method applied to the numerical solution of multimode slab waveguides with complex indexes

In order to obtain the numerical solution of multimode slab waveguides with complex indexes, we propose a method named RPS, which integrates real index numerical method, perturbation method and shooting method. This RPS method avoids searching the solution in the whole complex plane, meanwhile, it is simple, fast and precise. The application shows that the RPS method is suitable for both the transverse electric (TE) and the transverse magnetic (TM) mode.