Pan R-P, Tsai T-R, Chen C-Y, Pan C-L
Department of Electrophysics and the Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan 30010, R.O.C.
J Biol Phys. 2003 Jun;29(2-3):335-8. doi: 10.1023/A:1024485918938.
The complex refractive indices of two benchmark nematic liquid crystal,4-4 '-n-pentyl-cyanobiphenyl (5CB) and 4-(trans-4'pentylcyclohexyl)-benzonitrile (PCH5) have been determinedin the frequency range from 0.2 to 0.8 THz. The technique of coherent THztime-domain spectroscopy (THz-TDS) was used. We show that the birefringenceof 5CB is in the range of 0.15 to 0.21, while that of PCH is from 0.01 to0.08. Both liquid crystals exhibit relatively small absorption in thisfrequency range. The large birefringence of 5CB indicates possible applications of liquid-crystal-based devices for modulation and polarizationcontrol of electromagnetic radiation in the THz frequency range.
已在0.2至0.8太赫兹的频率范围内测定了两种基准向列型液晶4-4'-正戊基氰基联苯（5CB）和4-（反式-4'-戊基环己基）苯腈（PCH5）的复折射率。采用了相干太赫兹时域光谱技术（THz-TDS）。我们发现5CB的双折射在0.15至0.21范围内，而PCH的双折射在0.01至0.08之间。两种液晶在该频率范围内均表现出相对较小的吸收。5CB的大双折射表明基于液晶的器件在太赫兹频率范围内对电磁辐射进行调制和偏振控制方面可能具有应用价值。
