Novel liquid crystal filters for laser protection: understanding the physics of new modes and their incorporation in devices

液晶作为可切换的光学滤光片具有很大的潜力，因为它们具有响应性、快速性和出色的光消能。然而，目前还没有一种技术能够同时具备对激光照射进行有效动态保护所必需的特性。本提案开发了在光学滤光片中使用液晶的新方法。这些解决方案具有快速的潜力，可以切换到微秒级的时间尺度，具有高光密度，并提供吸收和反射选项。将采用的液晶模式包括：铁电和反铁电系统中的螺旋电变形；场致反射和非反射挫折相之间的相位变化，双稳态吸收模式；以及光学各向同性的电光效应。最后一种方法利用了液晶中一种全新的电光响应，这种响应在可切换技术中具有令人兴奋的潜力。除了探索全新电光开关模式的潜力外，我们还将研究新的器件模式，包括表面修饰以诱导双稳性，允许低功耗操作，并将液晶纳入全新的保护器件几何形状。

Liquid crystals have great potential as switchable optical filters as they are responsive, rapid and can offer excellent optical extinction. However, no current technology has the combination of properties necessary for effective dynamic protection against laser illumination. This proposal develops new approaches to using liquid crystals in optical filters. The solutions have the potential to be rapid, switching on the microsecond timescale, have high optical density, and offer both absorptive and reflective options. The liquid crystal modes that will be employed include: helielectric deformation in ferroelectric and antiferroelectric systems; field-induced phase changes between reflecting and non-reflecting frustrated phases, bistable absorptive modes; and optically isotropic electro-optic effects. The last approach makes use of an entirely new electro-optic response in liquid crystals that has exciting potential for switchable technology. In addition to exploring the potential of completely new electro-optic switching modes, we will examine new device modes that will include surface modifications to induce bistability, allowing low power operation, and including the liquid crystal in completely new protective device geometries.