中红外波段三明治结构的负折射效应  

Negative-index of a sandwich configuration in the mid-infrared region

作　　者：钱晓春[1] 杨理[1] 王燕[1] 叶永红[1] 

机构地区：[1]南京师范大学物理科学与技术学院,南京210023

出　　处：《中国科技论文》2013年第10期959-963,共5页China Sciencepaper

基　　金：高等学校博士学科点专项科研基金资助项目(20093207110012)

摘　　要：利用Ansoft HFSS有限元软件对响应在中红外波段周期结构的三明治薄膜超材料进行了S参数仿真,并对其负折射效应进行了优化研究。研究发现薄膜结构的负折射性质随着介质层厚度的变化而变化。通过对不同介质层厚度、孔及其反结构的金属-介质-金属薄膜的仿真,发现周期孔阵结构薄膜负折射效应的品质因数和带宽大致随介质层厚度的增加而增大,当介质层厚度达到1μm时,正方晶格和中心对称晶格的孔阵结构薄膜FOM值可分别达到0.542和0.544THz,负折射率带宽则可分别达到6.65、4.75THz。周期长条结构薄膜虽然没有这种规律,但当中心对称晶格长条结构的介质层厚度为0.5μm时,材料出现双负性质,品质因数和负折射率带宽可以分别达到6.20和0.935THz。In this paper, we simulate the S parameters and effective material parameters by Ansoft HFSS, and optimize the nega- tive refractive （NR） performance of the periodically structured metal-dielectric-metal sandwiched films. Our studies show that the NR properties vary with the thickness of the dielectric layer. By simulating metal-dielectric-metal hole array structure and its complementary （stripe） structure with different thicknesses of the dielectric layer, we find the figure of merit （FOM） and band- width of NR will increase with the increasing dielectric thickness for the hole array structure. When the dielectric layer of the pe- riodically tetragonal and centrosymmetry hole structure is 1 /~m thick, the FOM is 0. 542 and 0. 544 THz, and NR bandwidth is 6.65 and 4. 75 THz, respectively. The structure exhibits double negative when the dielectric thickness of periodically centrosymmetry strip structure is 0. 5μm. The FOM and NR bandwidth are 6.20 and 0. 935 THz, respectively.

关 键 词：光电子学与激光技术 薄膜超材料 负折射效应 中红外波段 

分 类 号：O734[理学—晶体学]