Algorri José Francisco, Bennis Noureddine, Herman Jakub, Kula Przemyslaw, Urruchi Virginia, Sánchez-Pena José Manuel
Opt Express. 2017 Jun 26;25(13):14795-14808. doi: 10.1364/OE.25.014795.
In this work, we present a novel kind of LC mixture (5005) for photonic applications, with emphasis on a LC microlens array. This mixture is a nematic composition of three different families of rod like liquid crystals. The key is that frequency dependence of parallel component of electric permittivity is different for each component, resulting in a strongly dependent on frequency dielectric anisotropy. The unique properties of this LC mixture are demonstrated to work in a frequency modulated LC microlens array. A hole patterned structure is used. Thanks to the special characteristics of this mixture, the microlenses are reconfigurable by low voltage signals with variable frequency. This is a first demonstration of a LC lens with tunable focal length by frequency in an analog way. The result of this type of control are microlenses with low aberrations and fast switching (the frequency switching is around 10 times faster than amplitude modulation). The tunability with frequency and the fast switching, makes this liquid crystal of special interest not only for microlenses but for all kind of optical phase modulators.
在这项工作中，我们展示了一种用于光子应用的新型液晶混合物（5005），重点是液晶微透镜阵列。这种混合物是由三种不同类型的棒状液晶组成的向列相组合物。关键在于每种组分的平行介电常数分量的频率依赖性不同，从而导致强烈的频率依赖性介电各向异性。这种液晶混合物的独特性质被证明可在调频液晶微透镜阵列中发挥作用。采用了孔图案化结构。由于这种混合物的特殊特性，微透镜可通过具有可变频率的低电压信号进行重构。这是以模拟方式首次展示通过频率实现焦距可调的液晶透镜。这种控制方式的结果是得到具有低像差和快速切换（频率切换比幅度调制快约10倍）的微透镜。频率可调性和快速切换特性使得这种液晶不仅对微透镜，而且对所有类型的光学相位调制器都具有特别的吸引力。
