基于一维光子晶体的角度选择吸波体

Angular Absorber Based on One Dimensional Photonic Crystal

提出了一种基于一维PC（光子晶体）的角度选择吸波结构,通过级联若干周期长度不同的PC,裁剪其光子带隙使得该吸波体波矢的实部和虚部仅在布鲁斯特角处有解,在380-700nm波段（全可见光波段）对以布鲁斯特角入射的p极化入射光实现了角度选择吸收,并且角度选择宽度小于5°。仿真结果表明,该吸波体对以布鲁斯特角入射的入射光的吸收率达99%以上,实现了完美吸收。以上结构能实现定向吸收,在太阳能转换等领域具有一定的应用前景。

The angular absorber based on one-dimensional Photonic Crystal （PC） has been proposed and investigated. The ab- sorber consists of multiple one dimensional PC, which has different periodicities. Both the real part and the imaginary part of the wave vector of the absorber will only have solutions at the Brewster angleby tailoring the overlap of the band gaps of these multiple one-dimensional PC. The absorber exhibits angular selectivity （the Brewster angle） in absorption within a broad wave- band from 380 nm to 700 nm （the visible wavelengths） under p-polarized illumination. It is also noted thatthe angular width in absorption is less than 5°. The simulation results show that the angular absorbance is above 99%, i. e. , perfect absorptionhas been achieved, when the incident lights illuminate on the absorber with the incident angle equalingto the Brewster angle. This feature of absorbing lights in a certain direction may have the potential in some new applications, such as solar thermophotovol- taic systems.