旋转对称性对红外超材料完美吸收器特性的影响

研究了超材料完美吸收器的旋转对称性对其吸收特性的影响.吸收器由金属颗粒/电介质/金属薄膜三层结构组成.以最上层是方形金属块为例,并通过在其y方向不同边沿处引入空气孔研究了四重、二重和非旋转对称吸收器的吸收特性.理论结果表明,当入射光偏振平行于x轴或y轴时,四重旋转对称结构有一个完全相同的吸收峰;二重旋转对称结构吸收峰会在入射光偏振平行于x轴时劈裂成两个峰;而无论入射光偏振平行于x轴或y轴,非旋转对称结构的吸收峰都会劈裂成两个峰.不同重数旋转对称性对吸收峰特性影响的结果将有助于设计新型的偏振无关的吸收器.

Impact of resonator rotational symmetry on infrared metamaterial absorber

The impact of rotational symmetry of the metamaterial perfect absorber on its performance was investigated. The absorber consists of a metal particle/dielectric-spacer/metal film structure. Using a square metal particle as an example structure and by introducing small air holes to the different y-direction sides of it, we study the absorption properties of the fourfold, twofold and non-rotational rotational symmetrical absorber. The calculated results show that when the polarization of the incident light parallels to x axis or y axis, the same single absorption peak appears in the absorption spectrum. The absorption peak of the twofold rotational symmetrical structure splits into two peaks when the polarization of the incident light parallels to x axis. The absorption peak splits into two peaks no matter the polarization of the incident light parallels to x axis or y axis in the case of non-rotational symmetry. The results of the absorption peak properties with different rotational symmetry may be helpful to design novel polarization-insensitive absorbers.