Abstract Nematic liquid crystals possess large and versatile optical nonlinearities suitable for photonics applications spanning the femtoseconds to milliseconds time scales, and across a wide spectral window. We present a comprehensive review of the physical properties and mechanisms that underlie these multiple time scales nonlinearities, delving into individual molecular electronic responses as well as collective ordered-phase dynamical processes. Several exemplary theoretical formalisms and feasibility demonstrations of ultrafast all-optical transmission switching and tunable metamaterials and plasmonic photonic structures where the liquid crystal constituents play the critical role of enabling the processes are discussed. Emphasis is placed on all-optical processes, but we have also highlighted cases where electro-optical means could provide additional control, flexibility and enhancement possibility. We also point out how another phase of chiral nematic, namely, Blue-Phase liquid crystals could circumvent some of the limitations of nematic and present new possibilities.

中文翻译：

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非线性光学、活性等离子体和液晶超材料

摘要 向列液晶具有大而通用的光学非线性，适用于跨越飞秒到毫秒时间尺度和宽光谱窗口的光子学应用。我们全面回顾了这些多时间尺度非线性背后的物理特性和机制，深入研究了单个分子电子响应以及集体有序相动力学过程。讨论了超快全光传输切换和可调谐超材料和等离子体光子结构的几个示例性理论形式和可行性演示，其中液晶成分在实现这些过程中起着关键作用。重点放在全光工艺上，但我们也强调了电光手段可以提供额外控制、灵活性和增强可能性的情况。我们还指出了手性向列相的另一相，即蓝相液晶如何绕过向列相的一些限制并提供新的可能性。