Analysis of photonic bandgap structure for a polaritonic photonic crystal in negative-index region

Abstract

A photonic bandgap (PBG) structure for a polaritonic photonic crystal (PPC) containing lithium tantalate (LiTaO 3 ) in the negative refractive index (NRI) region has been theoretically investigated. This region consists of a narrow frequency range of anomalous dispersion and a wide range of normal dispersion. The result shows that such PPC has a multiple-PBG structure with one gap located in the anomalous dispersion region and others in the normal dispersion region. PBG in the anomalous region is invariant with filling factor and scaling. This gap is further proven to be independent of the angle of incidence for both TE and TM nodes, leading to the existence of an omnidirectional gap. BPGs within the normal dispersion region are, however, strongly affected by the above three factors, especially for gaps near the upper limit of the NRI region.

Octonacci photonic crystals with negative refraction index materials

“…Also we show regions where the omnidirectional band gaps emerges for specific generations of Octonacci photonic structure, except for TM waves. On the other hand, M.-R. Wu et al [44], have studied theoretically the photonic bandgap structure for a polaritonic photonic crystal containing lithium tantalate (LiTaO 3 ) in the NRI region. They have concluded that in NRI region we have a multi band gap structure and that the gap falling in the anomalous dispersion region can be treated as a zero-index gap which is further shown to be omnidirectional.…”