Simulation and experimental study of electromagnetic wave localization in 3D dielectric fractal structures

Self-similar structures known as fractals have a potential to localize electromagnetic (EM) waves that are propagating through them. In this work 3D fractals called the Menger sponges were fabricated by using stereolithography from photosensitive epoxy resin mixed with titania-silica ceramic particles to localize EM waves in X band frequency range. The experiments in free space with 3D fractal structures have revealed clear attenuation of both reflection and transmission intensity at specific frequency. The FDTD simulations confirmed localization of electromagnetic energy in the sample, however, the simulated field distributions pointed out at resonance mode formation in small cavities and dielectric islands rather than in the central cavity.