High-birefringence nematic liquid crystal for broadband THz applications
High-birefringence nematic liquid crystal for broadband THz applications
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DOI：
10.1080/02678292.2016.1153732
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发表时间：
2016-01-01
期刊：
影响因子：
2.2
通讯作者：
Chu, Daping
中科院分区：
文献类型：
--
作者：
Li, Xuefeng;Tan, Nicholas;Chu, Daping
液晶由于其介电可调谐特性在可见光范围内得到了广泛的研究，由于对有源THz调制和开关器件的需求，在太赫兹(THz)范围内的特性也得到了越来越多的关注。在本文中，我们使用太赫兹时域光谱测量了一些商用和非商用向列型液晶显示器，包括E7，BL037，MDA98-1602，LCMS107，GT31825，在一定的偏置电压范围内，室温下的频率相关双折射和吸收系数。此外，还分析了LC混合物的几种基本成分，确定了它们对双折射的贡献，并用理论模型对吸收光谱进行了拟合。对一系列样品测量的大可调谐和低损耗表明，LCS是用于紧凑、高效和宽带THz器件的有用的可调谐介质。
Liquid crystals (LCs) have been studied extensively in the visible range for their dielectric tunability, and the characterisation in the terahertz (THz) range has gained increasing interest due to the need for active THz modulation and switching devices. In this paper, we use THz time-domain spectroscopy to measure the frequency-dependent birefringence and the absorption coefficient of a number of commercial and non-commercial nematic LCs, including E7, BL037, MDA-98-1602, LCMS-107, GT3-23001 and 1825, over a range of bias voltages at room temperature. Furthermore, several basic components of LC mixture are analysed to establish their contributions to birefringence and theoretical model is used to fit the absorption spectra. The large tunability and low loss measured for a range of samples show that the LCs are useful tunable dielectrics for compact, efficient and broadband THz devices.[GRAPHICS].