Adaptive mesh for computation of electromagnetic wave propagation through high refractive index dielectric structures

We consider spatial step selection for finite-difference solution of Maxwell's curl equations in presence of dielectric interfaces. If the contrast of the refractive indices is high, the wave number in optically thick medium decreases greatly and the fields oscillate fast. To improve accuracy, we propose a special quasi-uniform mesh which provides fine enough meshes in the vicinity of the interface and does not impose abundant computations in optically thin medium. The fundamental advantage of quasi-unform meshes in finite-difference is the possibility to obtain the solution simultaneously with its error value. We describe the corresponding procedure. © 2020 IOP Publishing Ltd.