Bridging the terahertz near-field and far-field observations of liquid crystal based metamaterial absorbers*
Bridging the terahertz near-field and far-field observations of liquid crystal based metamaterial absorbers*
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DOI：
10.1088/1674-1056/25/9/094222
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发表时间：
2016-07
影响因子：
1.7
通讯作者：
Lei Wang;Shijun Ge;Zhaoxian Chen;Wei Hu;Yan-qing Lu
中科院分区：
文献类型：
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作者：
Lei Wang;Shijun Ge;Zhaoxian Chen;Wei Hu;Yan-qing Lu
基于超材料的吸波材料在从能量收集和热发射器到传感器和成像设备的应用中发挥着重要的作用。传统超材料吸波材料的中间介电层一直是固体的。研究人员无法探测到这一层的近场分布，也无法有效地利用它。在这里，我们使用各向异性液晶作为介质层来实现电快可调谐太赫兹超材料吸波材料。我们展示了强烈的，位置相关的太赫兹近场增强，在超材料吸收体内具有亚波长分辨率。我们测量了太赫兹远场吸收随驱动电压的增加。通过将实验结果与液晶模拟相结合，我们间接验证了中间层的近场分布，并将近场和远场观测联系起来。我们的工作为创造可应用于生物成像和传感的高性能、快速、可调的太赫兹超材料设备开辟了新的机会。
Metamaterial-based absorbers play a significant role in applications ranging from energy harvesting and thermal emitters to sensors and imaging devices. The middle dielectric layer of conventional metamaterial absorbers has always been solid. Researchers could not detect the near field distribution in this layer or utilize it effectively. Here, we use anisotropic liquid crystal as the dielectric layer to realize electrically fast tunable terahertz metamaterial absorbers. We demonstrate strong, position-dependent terahertz near-field enhancement with sub-wavelength resolution inside the metamaterial absorber. We measure the terahertz far-field absorption as the driving voltage increases. By combining experimental results with liquid crystal simulations, we verify the near-field distribution in the middle layer indirectly and bridge the near-field and far-field observations. Our work opens new opportunities for creating high-performance, fast, tunable, terahertz metamaterial devices that can be applied in biological imaging and sensing.