一类慢变周期结构光子晶体的能带特性研究

Photonic Bandgaps in a Special Kind of Period-varying Photonic Crystal

本文构造了一种周期厚度保持不变 ,但相邻周期内部高低折射率区的厚度发生缓慢变化的变周期结构的光子晶体 ,并对其光子能带特性进行了分析。研究发现 ,本文所提出的两端带有慢变结构的光子晶体能够有效地拓宽光子能带带隙 ,与均匀结构相比 ,拓宽率可以达到 2 0 0 %以上。

We investigated a structure, which is made of many unit cells. There are two kinds of dielectric layers in each unit. The inside structures of adjacent cells are slightly different. However, we keep the size of each cell being the same. Surprisingly, we find that the width of the photonic bandgap of such a structure is very large. It is over 2 times larger than that of ordinary photonic crystals. Such a wide photonic bandgap may find applications in light controlling, in wide stop-band filtering, in solar energy utilizing and in heat energy engineering.