Huang Mu Lin, Cheng Yong Zhi, Cheng Zheng Ze, Chen Hao Ran, Mao Xue Song, Gong Rong Zhou
Engineering Research Center for Metallurgical Automation and Detecting Technology Ministry of Education, Wuhan University of Science and Technology, Wuhan 430083, China.
School of Electronic and Information Engineering, Hubei University of Science and Technology, Xianning 437100, China.
Materials (Basel). 2018 Mar 31;11(4):540. doi: 10.3390/ma11040540.
We present a simple design for a broadband tunable terahertz (THz) metamaterial absorber (MMA) consisting of a complementary cross-oval-shaped graphene (CCOSG) structure and dielectric substrate placed on a continuous metal film. Both numerical simulation and theoretical calculation results indicate that the absorbance is greater than 80% from 1.2 to 1.8 THz, and the corresponding relative bandwidth is up to 40%. Simulated electric field and power loss density distributions reveal that the broadband absorption mainly originates from the excitation of continuous surface plasmon resonance (SPR) on the CCOSG. In addition, the MMA is polarization-insensitive for both transverse-electric (TE) and transverse-magnetic (TM) modes due to the geometry rotational symmetry of the unit-cell structure. Furthermore, the broadband absorption properties of the designed MMA can be effectively tunable by varying the geometric parameters of the unit-cell and chemical potential of graphene. Our results may find promising applications in sensing, detecting, and optoelectronic-related devices.
我们提出了一种宽带可调谐太赫兹（THz）超材料吸收器（MMA）的简单设计，该吸收器由互补交叉椭圆形石墨烯（CCOSG）结构和置于连续金属膜上的介电基板组成。数值模拟和理论计算结果均表明，在1.2至1.8太赫兹范围内吸光度大于80%，相应的相对带宽高达40%。模拟的电场和功率损耗密度分布表明，宽带吸收主要源于CCOSG上连续表面等离子体共振（SPR）的激发。此外，由于单元结构的几何旋转对称性，该MMA对横向电（TE）和横向磁（TM）模式均不敏感。此外，通过改变单元的几何参数和石墨烯的化学势，可以有效地调节所设计MMA的宽带吸收特性。我们的结果可能在传感、检测和光电子相关器件中找到有前景的应用。
