Thickness-dependent transmission in a finite photonic crystal containing nearly ferroelectric superconductor

In this paper, anomalous transmission properties in a finite photonic crystal made of a nearly ferroelectric superconductor, and a dielectric have been theoretically investigated. We show that, in the thickness domain, the transmission spectrum can be divided into two different regions: nonresonance and resonance. There are resonant transmission peaks in the resonance region, and the number of peaks is strongly dependent on the number of periods. In the frequency response, the number of resonant peaks is also increased as the thickness of nearly ferroelectric superconductor increases. The appearance of anomalous peaks enables us to design a narrowband filter without introducing any defect layer into the photonic crystal.