h-BN型超晶格等离子体光子晶体能带特性研究

六方氮化硼(h-BN)晶格结构是一种类六方对称复式超晶格结构。具有h-BN晶格构型的光子晶体以其宽光子带隙特点受到国内外学者的广泛关注。本文利用不同尺度低压气体放电管与Al₂O₃介质棒周期性排列，构建了新型h-BN型超晶格等离子体光子晶体，实现其空间结构和等离子体参数的动态调控。利用微波透射谱对比研究了h-BN型超晶格与简单三角晶格等离子体光子晶体禁带位置、宽度和数目。分析了放电电流、介质棒阵列数对不同频段光子带隙的影响，以及电磁波入射角度对电磁传输特性的影响。结果表明：等离子体的引入不仅能够形成新的光子带隙，而且可以选择性地使部分禁带位置发生移动；相对于简单三角晶格，h-BN型超晶格等离子体光子晶体呈现出更多光子带隙；Al₂O₃介质棒阵列数对等离子体光子晶体禁带位置、宽度和数目均具有重要影响。电磁波入射角度变化越大，电磁传输特性差别越显著，透射谱相关性越差。本文所设计的新型h-BN型超晶格等离子体光子晶体为制作可调谐光子晶体提供了新的思路，在微波和太赫兹波控制领域具有潜在应用价值。

Band Gap Characteristics of h-BN Superlattice Plasma Photonic Crystals

Hexagonal boron nitride (h-BN) lattice structure is a kind of hexagonal symmetric complex superlattice structure. In recent years, photonic crystals with h-BN superlattice structure have attracted growing attentions due to their unique properties of wide photonic band gaps. A new h-BN superlattice plasma photonic crystal (SPPC) constructed by periodically arranging gas discharge tubes and Al₂O₃ dielectric rods is proposed in this paper. The positions, widths and numbers of band gaps for h-BN superlattice and triangular lattice plasma photonic crystal (PPC) have been compared. The effects of the discharge current, numbers of dielectric rod rows and incident angles of electromagnetic waves in different frequencies have been demonstrated. The results show that the introduction of plasma enables tunable structural configurations and plasma parameters for h-BN SPPC. It not only produces new photonic band gaps, but also selectively shifts the band gap positions. Compared with the simple triangular PPC, h-BN SPPC possesses more photonic band gaps. Moreover, the numbers of dielectric rod rows have significant influences on the positions, widths and numbers of band gaps. The correlation of transmission spectra decrease with the increase of incident angle of electromagnetic waves. The novel h-BN SPPC suggested in this work provides some inspiration for creating new types of tunable metamaterials, which has potential applications in the manipulation of microwave and terahertz waves.