两端有慢变结构的光子晶体的能带特性研究

研究了几种两端有慢变周期结构的光子晶体的能带特性，研究发现，通过在普能光子晶体两端添加适当的慢变周期结构，可以使光子晶体的光子禁带区向短波区或向长波区扩展，也可以同时向短波和长波两个区域扩展，与普通结构的光子晶体的光子禁带宽度相比，可以获得400％以上的禁带区宽度的拓展。

Photonic Bandgaps in Photonic Crystals with Tapered Periods at Both Ends

Photonic crystals with slowly varying period structures added to the two ends of an ordinary photonic crystal are investigated. It is found that the photonic bandgap region can be extended toward the short wavelength region, the long wavelength region, or the both by adding proper period-tapering structures at the both ends of an ordinary photonic crystal. The photonic bandgap of such structures can be very large. It can be over 4 times as large as that of ordinary photonic crystals. Such a wide photonic bandgap may find application in controlling light, in wide stop-band filtering, in solar energy utilization and in heat energy engineering.