Photonic Band Gap and Fractal Resonances in Aperiodic Cantor-like Self-Similar a:SiN_x Photonic Structures

Abstract

Aperiodic (quasi-periodic) photonic crystal-like fractal resonant cantor set structures exhibit self-similarity and self-scaling features. The optical features of fractal resonances in various orders of cantor structures are successfully visualized by transfer matrix simulations. The unsymmetric and self-similar nature and variation in the intentionally introduced optical defect layer result in a strong microcavity-like structure. The optimized cantor (order-2)-based distributed Bragg reflector (DBR) and microcavity-like one-dimensional (1D) photonic structures are fabricated using nonstoichiometric compositions of a:SiN x dielectric layers of reasonable refractive index contrast (n L = 1.8 and n H = 2.7). The sharp photonic resonances and the microcavity quality factor are relatively high for cantor-based fractal resonant aperiodic photonic structures, with respect to the conventional periodic and hybrid counterparts. The demonstrated evidence of a:SiN x -based fractal cantor quasiperiodic photonic crystal features and their temperature tunability provides a platform for many varieties of optoelectronic applications and an alternative to the conventional periodic photonic structures.