Ultrawide photonic band gaps with the limit of gap-midgap ratio of 200% produced from complete-connected networks

A kind of one-dimensional (1D) complete-connected network (CCN) is designed and its extraordinary optical property for producing an ultrawide photonic band gap (PBG) is investigated. The gap-midgap ratio formulaes of the largest PBGs created by CCNs are analytically derived, and the results indicate that with the increment of the node number in a unit cell, the number of the loops that can produce antiresonances increases fleetly, and consequently the gap-midgap ratio of the PBG produced by CCNs enlarges rapidly and tends rapidly to the limit at 200%. Moreover, the general transmission formula for 1D CCNs is analytically determined. Due to the periodicity, two types of transmission resonance peaks are generated, and the condition is analytically obtained from the transmission formula. This kind of CCN may have wide applications to design superwide band optical filters, optical devices with large PBGs and strong photonic attenuations, and other related optical communication and optical increment processing devices. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

A one-dimensional complete-connected network is designed to investigate its extraordinary optical property for producing an ultrawide photonic band gap. Analytical formulas are derived for the gap-midgap ratio of the largest PBGs created by CCNs and the general transmission formula for 1D CCNs. This network has wide applications in designing optical filters, devices with large PBGs, and optical communication devices.