Optical polarization states of a liquid-crystal blue phase II
Optical polarization states of a liquid-crystal blue phase II
复制标题
液晶蓝相 II 的光学偏振态
作者：
Hui;Hao Tu
展望了蓝相光电器件的优越性和独特性。本文给出了BPII的透射光和反射光的相关电光行为，并试图通过研究光的偏振态来解释这些现象。在计划内开关BPII电池中可以看到两个阶段的电光行为。由于克尔效应，线偏振光的双折射在150v时被诱导并饱和0.021，克尔常数约为3乘以10^{-10}；{extrm {mV}} ^{2} $≈3×10 10 mV−−2。由于外加电压较强（>200 V），晶格结构变形的影响支配了不同波长处的透射/反射强度，导致透射光强度发生不连续变化，透射光偏振态的方位角（$80^{circ}$80°）发生巨大变化。结果表明，BPII晶格结构的变形不仅引起线性双折射，而且引起旋光功率的变化，进而影响光的偏振态。这些实验结果表明，BPII细胞的电光性质比众所周知的BPI相更为复杂。他们还表明，BPII不仅可以用于反射器件，还可以用于场可调谐光学器件。
The advantages and uniqueness of blue-phase-based electro-optical devices are predicted. In this paper, we present relevant electro-optics behaviors of the transmitted and reflected lights of BPII and try to explain those phenomena through studying the polarization states of the lights. There are two stages of electro-optical behaviors seen in an in-plan-switching BPII cell. Because of the Kerr effect, the birefringence of the linear polarized light is induced and saturated 0.021 at 150 V, and the Kerr constant is $approx 3 imes 10^{-10}; { extrm{mV}}^{-2}$≈3×10−10mV−2. As the applied voltage is stronger (>200 V), the influence of the deformation of the lattice structure dominates the transmitted/reflected intensity at different wavelengths, which causes a discontinuous change in the transmitted light intensity and a huge variation in the azimuth angle ($80^{circ }$80∘) of the polarization state of the transmitted light. As a result the deformation of the lattice structure of the BPII not only induces a linear birefringence but also induces a change in optical rotatory power and then affects the polarization state of the light. These experimental results show that the electro-optical nature of the BPII cell is more complicated than the well-known BPI phase. They also show that BPII can be used not only in transflective devices, but also in field-tunable optical devices.