Novel Electro-optic and Photonic Behaviours in Bent Core Liquid Crystals

液晶是一种自组织的流体，它显示出一系列引人注目的结构，每一种结构都有细微不同的物理性质。它们最著名的应用是在液晶设备（LCD）上，这是一项非常成功的技术，它将雪茄状的分子组织起来，使它们的长轴平均指向一个可以被电场控制的方向。它们形成的有序结构是双折射的，因此与偏振光相互作用，当双折射和偏振光的传输被电压调制时，lcd就产生了。控制分子的形状和结构可以形成不同的液晶相，并为控制许多理想的性能提供了途径。在本提案中，我们的目标是开发一些非常新的研究，其中分子结构具有弯曲核，从而导致一类新的向列液晶，其特性包括铁电性，双轴性，增强的挠性，不寻常的粘弹性行为以及新的电光效应。我们建议生产这种室温的材料，并对其物理性质有详细的了解。我们希望这将引导我们找到一种新的快速开关，可以用于显示器或其他类型的电光设备。例如，我们预计这些材料中的一些将表现出光学非线性-这意味着当红光照射到它们中时，蓝光会出现（这被称为倍频），这些材料可以用于光子器件，如激光器。研究周期很短，因为我们希望在瞬息万变的主题领域迅速利用我们现有的专业知识。我们相信，我们可以在一年内完成足够的研究，在一个我们拥有所有必要实验方法的环境中，使用训练有素的人员，了解哪些领域需要进一步研究，哪些领域可以立即产生成熟的技术，通过“跟进”或其他知识交流机制转让给我们的工业同事。因此，我们期望这个研究项目具有很高的成本效益，在这些系统的基础上发表几篇高质量的论文，并在我们将一些最有趣的技术转让给我们的工业同事时产生很大的影响。

Liquid crystals are self-organizing fluids that display a remarkable array of structures, each of which has subtly different physical properties. They are best known for their use in liquid crystal devices (LCD), a hugely successful technology in which cigar-shaped molecules are organized so that on average their long-axes point along a direction that can be controlled by an electric field. The ordered structure they form is birefringent, so interacts with polarized light, and LCDs result when the birefringence, and hence transmission of polarized light, is modulated by a voltage. Control of the molecular shape and structure can result in the formation of different liquid crystal phases and offer a route to control many desirable properties. In this proposal, we aim to exploit some very new research in which the molecular structure has a bent-core, leading to a new class of nematic liquid crystals with properties that can include ferroelectricity, biaxiality, enhanced flexoelectricty, unusual visco-elastic behaviour and therefore new electro-optic effects. We propose to produce such materials that are room-temperature and to generate a detailed understanding of their physical properties. We expect that this will lead us to new kinds of fast switching that could either be used in displays or indeed in other kinds of electro-optic devices. For example, we expect that some of these materials will exhibit optical nonlinearity - this means that when red light is shone into them, blue light emerges (this is known as frequency doubling), and such materials find uses in photonic devices such as lasers.The research period is a short one as we wish to make rapid use of our existing expertise in a subject area that is changing rapidly. We believe that we can carry out sufficient research in a year, using fully trained personnel in an environment where we have all of the necessary experimental methods at our fingertips, to understand which areas need further research, and which can lead immediately to technology that is ripe for transfer to our industrial colleagues via 'follow on' or other knowledge exchange mechanisms. Therefore, we expect this research programme to be very cost-effective, delivering several high-quality papers on the fundamentals of these systems, and also to lead to high impact as we transfer some of the most interesting technology to our industrial colleagues.