Liquid crystal tunable terahertz lens with spin-selected focusing property
Liquid crystal tunable terahertz lens with spin-selected focusing property
复制标题
具有自旋选择聚焦特性的液晶可调谐太赫兹透镜
DOI：
10.13641/oe.27.008800
复制
发表时间：
2019-03-18
期刊：
影响因子：
3.8
通讯作者：
Hu, Wei
中科院分区：
文献类型：
--
作者：
Shen, Zhixiong;Zhou, Shenghang;Hu, Wei
我们提出并演示了一种太赫兹（T1-1z）范围的液晶（LC）主动自旋选择透镜。该透镜是两个具有分离中心和共轭相位轮廓的几何相位透镜的叠加。它的数字化多向LC定向是通过动态微光刻技术实现的，并被两个石墨烯电极覆盖的二氧化硅衬底夹在中间。这种特殊的透镜可以分离出具有相反圆偏振的入射光的聚焦点。利用扫描近场太赫兹显微镜系统对其在0.8 ~ 1.2太赫兹的聚焦性能进行了表征。偏振转换效率在32.1% ~ 70.2%之间变化。自旋选择聚焦函数与数值模拟结果吻合较好。该透镜具有动态功能、低插入损耗和宽带适用性等优点。它可以启发各种实用的太赫兹仪器。(C) 2019年美国光学学会根据OSA开放获取出版协议的条款。
We propose and demonstrate an active spin-selected lens with liquid crystal (LC) in the terahertz (T1-1z) range. The lens is a superposition of two geometric phase lenses with separate centers and conjugated phase profiles. Its digitalized multidirectional LC orientations arc realized via a dynamic micro-lithography-based photo-patterning technique and sandwiched by two graphene-electrode-covered silica substrates. The specific lens can separate the focusing spots of incident light with opposite circular polarizations. Its focusing performance from 0.8 to 1.2 THz is characterized using a scanning near-field THz microscope system. The polarization conversion efficiency varies from 32.1% to 70.2% in this band. The spin-selected focusing functions match well with numerical simulations. Such lens exhibits the merit of dynamic functions, low insertion loss and broadband applicability:. It may inspire various practical THz apparatuses. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.