基于高阻硅超表面结构的太赫兹聚焦透镜设计

Design of terahertz focusing lens based on highresistivity silicon metasurface

本文利用亚波长硅圆柱组成的超表面设计了用于太赫兹探测器的聚焦透镜,通过改变硅柱的直径,实现对太赫兹波传输相位0~2π的调控。在1 THz频率下,所设计的单面超表面透镜,太赫兹波电场能量密度提升到入射平面波的32倍。基于工艺制备可行性和抗反射考虑,提出了一种双面超表面透镜,将电场能量密度提升到入射平面波的44倍。对比于传统超半球太赫兹硅透镜,超表面透镜具有厚度薄,体积小的优点,有利于太赫兹探测器组件的小型化,为实现与太赫兹探测器的集成提供了可能性。

In this paper,a focusing lens for terahertz detection is designed using a metasurface composed of sub-wavelength silicon cylinders.By tuning the diameter of the silicon cylinder,the transmission phase of the THz wave is controlled from 0 to 2π.At 1 THz,the terahertz electric field energy density focused by the single-sided metasurface lens designed can be increased to 32 times that of the incident wave.After adding the anti-reflection,a double-sided metasurface lens is proposed,which is feasible in processing,increasing the electric field energy density to 44 times that of the original.Compared with the traditional hyper-hemispheric terahertz silicon lenses,our metasurface lens has the advantages of thin thickness and small volume,which is conducive to the miniaturization of the terahertz detector component and provides the possibility to realize the integration with the terahertz detector.