近年来，太赫兹传感技术取得了长足的发展，在广泛的领域中展现出了可观的应用价值，因此对太赫兹传感设备的性能不断提出更高的要求。太赫兹超材料吸波体可对太赫兹波进行吸收，而它的性能对外界的影响（如折射率变化）具有极高的敏感性。然而目前如何改进太赫兹超材料吸波体的设计，以提高其在传感应用中的灵敏度仍是亟待解决的问题。针对该问题，本文进行了以下研究：

设计了一种采用双金属环谐振器的吸波体结构，在1.998THz和4.422THz两个频点处分别产生了吸收率为90.8%和96.38%的吸收峰。在周围环境折射率传感的仿真中，谐振器间的耦合提升了灵敏度，所提出的吸波体结构展现出了S=2.507THz/RIU，Q_max=205.67，FOM_max=113.84RIU^-1的高传感性能。最后，从等效电路模型的角度出发分析了吸波体的传感特性，并通过电路仿真进行了验证。

为进一步提升吸波体在传感时的灵敏度，将谐振器的材料由金属替换为石墨烯，并通过旋转顶层十字形谐振器得到了补丁形吸波体设计。在3.684THz和4.412THz两个频点处分别产生了吸收率高达99.21%和99.24%的吸收峰，实现了双频点的完美吸收。在周围环境折射率传感的研究中，该吸波体结构展现出了S=3.074THz/RIU，Q_max=367.67和FOM_max=295.65RIU^-1的高传感性能，相比于采用金属材料谐振器的吸波体具有更高的灵敏度。

通过优化石墨烯谐振器的设计，利用谐振器之间的耦合进一步提高了吸波体的性能。在4.962THz和5.662THz两个频点处分别产生了吸收率高达99.45%和99.64%的吸收峰。在周围环境折射率传感的仿真中，所提出的吸波体结构具有S=4.071THz/RIU，Q_max=493.45和FOM_max=380.53RIU^-1的传感性能，相比上一章的简单设计，通过优化谐振器设计进一步提升了传感的灵敏度。最后，仿真得到了吸波体表面涂覆待测物时的灵敏度并分析了待测物厚度对灵敏度的影响。

本文所提出的吸波体结构设计，通过更换谐振器材料、优化谐振器设计的方式提高了吸波体的性能，同时进一步提升了太赫兹超材料吸波体传感应用的灵敏度，展现出了在太赫兹传感技术中的巨大应用前景。

In recent years, terahertz sensing technology has made great progress and exhibited considerable applying value in wide range. Thus, there is a need to improve the performance of terahertz sensing devices continually. Terahertz metamaterial absorbers have capacity of absorbing terahertz wave, and the performance of the absorber is high sensitive of environment influence (such as variation of refractive index). Nonetheless, it still is a problem need to solve that achieving higher sensitivity in application of sensing by optimizing the design of absorber. Thus, this thesis focus on this problem, and the researches as follows are carried on:

We have proposed a structure of absorber with double metal-ring resonator, whose absorptivity are 90.8% and 96.38% at 1.998THz and 4.422THz, respectively. The simulation results of surrounding environmental refractive index sensing show that the high sensing performance of the proposed absorber are S=2.507THz/RIU, Q_max=205.67, FOM_max=113.84RIU^-1, respectively. It is owing to the coupling of ring resonators. The refractive index sensing performance was further investigated through the equivalent circuit model, whose sensitivity fits the corresponding result from CST well.

To improve the sensitivity of the absorber, we changed the material of resonators from metal to graphene and suggested a patch absorber based on the typical design of cross absorber. The absorptivity of the suggested absorber are 99.21% and 99.24% at 3.684THz and 4.412THz respectively,which means the achievement of dual-band perfect absorption.The simulation results of surrounding environmental refractive index sensing show that the high sensing performance of the proposed absorber are S=3.074THz/RIU, Q_max=367.67, FOM_max=295.65RIU^-1,

respectively. Thus, the using of graphene makes the absorbers more sensitive in sensing application.

The performance of the proposed absorber was improved through optimizing the design of resonators. At 4.962THz and 5.662THz, there are two absorption peaks with the absorptivity of 99.45% and 99.64%, respectively. In surrounding environmental refractive index sensing, the simulation results show the high sensing performance of S=4.071THz/RIU, Q_max=493.45, FOM_max=380.53RIU^-1, which is due to the optimization of resonators design. Finally, simulating the sensing performance when the analyte covered the surface of the absorber and investigating how the thickness of analyte influence the sensitivity.

The structural design of the absorbers proposed in this thesis enhanced the absorptivity and the sensitivity by optimizing the material and design of resonators. Additionally, our designs show the considerable application prospect in terahertz sensing technology.