Multiband Adjustment Engineering Strategy for Broadband Range in Photonic Crystals

Abstract

Abstract: Topological edge states are crucial for optical modulation, and the overlapping Brillouin zones in double-layered structures can effectively control multiband edge states. A bilayer photonic crystal framework can enhance the rotational freedom, providing additional functionalities. In this study, a multifunctional, tunable, innovative double-layer C 4  nested photonic crystal structure was developed; it reached a higher degree of freedom via double independent rotations. These double-nested C 4  photonic crystal structures could expand the functional range of C 4  structure implementation. The multifunctional implementation of multienergy band transmissions, unidirectional transmissions, and wavelength division multiplexers containing double-nested C 4  structures were experimentally demonstrated. The experimental results agreed well with the simulated predictions. Thus, this study offers new insights and strategies to foster the advancement of topological photonics and radar communication devices.

Keywords: Photonic crystals, multienergy band transmissions, multiband adjustment, wavelength division multiplexing