双控石墨烯超材料太赫兹调制器的双频反射特性（英文）  

Reflection Modulation Properties at Two Frequencies of Dual-control Graphene Metamaterial Terahertz Modulator

作　　者：张玉萍[1] 吕欢欢[1] 李彤彤[1] 张会云[1] 

机构地区：[1]山东科技大学电子通信与物理学院,山东青岛266590

出　　处：《山东科技大学学报（自然科学版）》2016年第6期68-75,共8页Journal of Shandong University of Science and Technology(Natural Science)

基　　金：国家自然科学基金项目(61001018);山东省自然科学基金项目(ZR2016FM09);山东省高等学校科技计划项目(J13LN16);青岛市创新领军人才项目(13-CX-25);中国工程物理研究院太赫兹科学技术基金项目(201401);青岛经济技术开发区重点科技计划项目(2013-1-64);山东科技大学研究生创新基金项目(YC150354)

摘　　要：设计了双控太赫兹超材料调制器,并研究了其在太赫兹频段内两个频率处的反射特性。该调制器由开口环谐振器及其底部的"三明治"结构组成,"三明治"结构从上到下依次为石墨烯层、聚酰亚胺层和金层,其中开口谐振器的开口处填充硅。该结构可以通过电、光两种方式调制,即分别对调制器中的石墨烯施加低电压,对硅施加弱光照。结果显示:反射谱在频率0.806THz、1.869THz出现两个共振反射谷,在满足低激励的条件下,增强两种激励均能改变共振反射谷的反射强度。两个共振处的反射调制方向表现出先反向、后同向的特点,其临界点对应的石墨烯费米能级和硅电导率分别为13.489meV、970.54S/m。文章对同时施加两种激励的情况进行了详细研究,结果表明:同时施加两种激励的调制特性并非单独施加激励的数值叠加,电、光两种调制方式相互独立。在调制过程中,调制器出现的最大调制深度为99.74%。A dual-control terahertz metamaterial modulator was proposed,whose reflection properties at two frequencies in the terahertz frequency range can be tuned by voltage and illumination.The metamaterial modulator is composed of a split-ring resonator,which is deposited on a sandwich structure of a graphene layer,a polyimide spacer layer and a gold layer,embedded by semiconductor silicon in the split gap.The study was achieved by applying low bias voltage on graphene layer and weak light intensity on semiconductor,respectively.The results demonstrate two reflection dips in the reflective spectrum, moreover,both excitations can change the strength of resonance reflection dip.The resonance reflection dip at 0.806 THz rises with the increasing of the Fermi level or the light intensity.While at 1.869 THz,the resonance reflection dip first decreases and then increases,reaches its minimum at Fermi level of 13.489 meV and light pump of 970.54 S/m,respectively.Numerical results with two external stimuli changing simultaneously are also presented.The best amplitude modulation depth that could be achieved is 99.74% at 0.806 THz with the Fermi level changes from 0.2 meV to 60 meV.

关 键 词：双控 石墨烯 太赫兹反射调制器 弱激励 强调制 

分 类 号：O433[机械工程—光学工程]