Ultra-large omnidirectional photonic band gaps in one-dimensional ternary photonic crystals composed of plasma, dielectric and hyperbolic metamaterial

摘要

Owing to the Bragg interference mechanism, photonic band gap (PBG) in all-dielectric one-dimensional photonic crystal (PC) is strongly sensitive to the incident angle, which limits the width of omnidirectional photonic band gap (OPBG). Recently, researchers realized a kind of special PBG called angle-insensitive PBG in one-dimensional binary PC composed of alternating dielectric and hyperbolic metamaterial (HMM) layers. Different from the conventional strongly angle-insensitive PBG, this kind of PBG is angle-insensitive and naturally omnidirectional, providing us an efficient way to achieve ultra-large OPBG. In this paper, by periodically introducing plasma layers into one-dimensional binary PC composed of alternating dielectric and HMM layers with angle-insensitive PBG, we find that the PBG can be efficiently broadened. Although the PBG becomes slightly angle-sensitive since the introduction of plasma layers breaks the phase variation compensation condition, the width of OPBG can still be efficiently broadened. Under the proper design, we achieve an ultra-large OPBG with the width up to 1321 nm (68% relative bandwidth) in the one-dimensional ternary PC composed of alternating plasma, dielectric and HMM layers at near-infrared wavelengths. The whole one-dimensional ternary PC is composed of only three kinds of materials: indium tin oxide (ITO), silicon (Si) and silicon carbide (SiC), which can be fabricated by the atomic layer deposition (ALD) method under the current experimental conditions. This ultra-large OPBG in simple one-dimensional structure could be utilized to design ultra-broadband omnidirectional optical mirror and narrowband optical filter with ultra-large omnidirectional stopband.