光学学报, 2014, 34 (1): 0123002, 网络出版: 2014-01-02
红外波段十字阵列光吸收材料光学特性研究
Optical Properties of Cross-Shaped Array Optical Absorber in the Infrared Region
光学器件 完美吸收材料 散射参数 红外探测 谐振吸收 optical devices perfect absorber scattering parameters infrared detection resonance absorption
摘要
尺寸为光波长量级的微纳结构材料与电磁波的相互作用,使得其具有许多特殊的光学性能,金属电介质金属微纳结构具有电磁波完美吸收特性。基于S参数法,研究十字阵列光吸收材料在红外波段的光学特性参数,分析其谐振吸收机理及光学特性参数调谐性。研究结果表明,十字阵列单元尺寸对其等效光学参数具有调谐作用;当材料表面与入射介质之间满足阻抗匹配条件,以及等效折射率系数虚部值足够大时,可以有效提高其吸收率;经过结构优化的十字阵列光吸收材料在红外波段具有大于95%的吸收率,实验样件测试结果大于80%。十字结构臂长和电介质层厚度决定吸收谱特性,而十字结构臂宽仅仅影响吸收谱峰值大小。十字阵列光吸收材料在红外波段的完美吸收及光谱调谐性特点,使其可用于红外探测和光谱成像等领域。
Abstract
Metamaterials have many exotic optical properties due to the interaction between the electromagnetic wave and the nanostructures. Metamaterials (PAMs) with metal-dielectric-metal structure have perfect absorption characteristics. The optical parameters of a cross-shaped absorber in infrared band are retrieved by the S-parameters method. The mechanism of resonant absorption and optical tunability are studied. The experiments and simulations results indicate that the size of cross-shaped absorber can tune its effective optical parameters and can effectively increase its absorptivity on the conditions that the effective impedance matches well to the incident medium, and the imaginary part of the effective refractive index approaches as great value as possible. The absorptivity of optimized cross-shaped absorber is greater than 95% and maximum absorption of 80% is experimentally obtained in infrared region. The resonance peaks of the absorption spectrum depends on the length of the cross arm and thickness of the dielectric materials, while the width of the cross arm plays a critical role to the maximum absorption value. The characteristics of perfect absorption and spectral tenability of corss-shaped absorber make it promising in many applications, including infrared detection, spectral imaging and so on.
黎永前, 苏磊, 王斌斌, 郭勇君, 寿宸. 红外波段十字阵列光吸收材料光学特性研究[J]. 光学学报, 2014, 34(1): 0123002. Li Yongqian, Su Lei, Wang Binbin, Guo Yongjun, Shou Chen. Optical Properties of Cross-Shaped Array Optical Absorber in the Infrared Region[J]. Acta Optica Sinica, 2014, 34(1): 0123002.