摘要
研究了一种由十字形石墨烯图案和4L形石墨烯图案构成且对偏振及角度不敏感的类电磁诱导透明超材料结构,而图案的对称性会导致该超材料结构在太赫兹波段表现出优异的偏振不敏感特性。结果表明,在横电(TE)偏振和横磁(TM)偏振的条件下,当太赫兹波的入射角度在0°~60°之间变化时,透射峰的强度均可保持在0.75以上,表现出良好的入射角不敏感特性。通过对拆分结构的透射谱、谐振频率处电场强度及表面电流分布进行分析,研究类电磁诱导透明效应产生的物理机制,进一步分析谐振单元的长度对类电磁诱导透明窗口的影响。结果表明,该超材料结构在太赫兹波段具有明显的慢光效应和较高的折射率灵敏度。通过改变石墨烯的费米能级可以同时对透明窗口、群延时及折射率灵敏度进行调控,该性质在光缓存器件和传感器领域有重要的应用价值。
Objective The quantum coherent effect of electromagnetic induced transparency(EIT)is characterized by a narrow transmission peak in a broad absorption band.This phenomenon is associated with the slow light effect,which can be used in optical buffering,refractive index sensing,and other applications.And the development of the EIT effect has been limited due to the extremely difficult implementation conditions.Metamaterials are artificial composite materials made from natural materials with unique physical and chemical properties that natural materials do not have.Adjusting the resonant frequency of bright and dark modes to make them resonant at a close frequency and then combining them to produce an atom-like electromagnetic induced transparency phenomenon is how EIT-like behavior in metamaterial is generally realized.However,in some reported research,the passive modulation method is used in EIT-like metamaterial,which greatly limits the application of related devices.Therefore,studying EIT-like metamaterials in the terahertz band under active regulation is an important research topic.Electronic control is now widely used due to its simple operating conditions.In general,electronic control can be achieved by incorporating electrically adjustable devices,such as variograms and other electrically tunable materials.The reported graphene structures are typically polarization-and incident-angle-sensitive,with the transmission peak disappearing under oblique incidence.Because of numerous possibilities for the polarization direction and angle of the incident wave in practical applications,polarization-and angle-insensitive metamaterial devices are more suitable for application requirements.The proposed structure shows excellent characteristics,such as polarization-independence,incident angle-insensitivity,obvious slow light effect,and high refractive index sensitivity.Methods A novel polarization-and angle-insensitive metamaterial structure based on the cross and 4L-shaped graphene is designed.CST Microwave Studio softwa
作者
吕宇玲
延凤平
杜雪梅
王伟
Lu Yuling;Yan Fengping;Du Xuemei;Wang Wei(Key Laboratory of All Optical Network and Advanced Telecommunication Network,Ministry of Education,Institute of Lightwave Technology,Beijing Jiaotong University,Beijing 100044,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2021年第23期184-194,共11页
Chinese Journal of Lasers
基金
国家自然基金(61827818,61620106014)。
关键词
材料
超材料
类电磁诱导透明
太赫兹
石墨烯
偏振及角度不敏感
materials
metamaterials
electromagnetically induced transparency-like
terahertz
graphene
polarization-and angle-insensitivity
