基于石墨烯超材料的太赫兹五频段折射率传感器

Terahertz Pentaband Refractive Index Sensor Based on Graphene Metamaterial

针对目前太赫兹折射率传感器波段单一且灵敏度低的问题,提出一种基于石墨烯超材料的五频段折射率传感器。通过CST电磁仿真软件对传感器结构进行模拟仿真,确定了可以同时提高吸收率和灵敏度的特征尺寸。与传统超材料折射率传感器相比,通过调整石墨烯层的化学势和弛豫时间即可实现石墨烯吸收体的可调谐性。仿真结果表明,该折射率传感器在频率为4.535、6.3681、8.253、10.395和11.321 THz时达到折射率吸收峰值,吸收率分别为92.2%、99.5%、99.9%、90%和99.1%,且5个波段中最高折射率灵敏度为436 GHz/RIU。与其他折射率传感器相比,该折射率传感器波段多且灵敏度高,具有良好的传感性能,可应用于光学检测、医学成像、生物传感等领域。

Aiming at the problems of the current terahertz refractive index sensor with a single band and low sensitivity,a graphene metamaterial based pentaband refractive index sensor was proposed.The sensor structure was simulated by CST electromagnetic simulation software to determine the characteristic dimensions that could increase the absorption rate and sensitivity simultaneously.Compared with conventional metamaterial refractive index sensors,the tunability of graphene absorber was achieved by adjusting chemical potential and relaxation time of the graphene layer.The simulation results show that the refractive index sensor has refractive index absorption peaks at 4.535,6.3681,8.253,10.395 and 11.321 THz,and the absorption rates are 92.2%,99.5%,99.9%,90% and 99.1%,respectively.The maximum refractive index sensitivity is 436 GHz/RIU in the five bands.Compared with other refractive index sensors,the proposed refractive index sensor has good sensing performances such as multi-frequency band and high sensitivity,which can be used in fields of optical detection,medical imaging,biosensor,etc.