Palffy-Muhoray Peter, Cao Wenyi, Moreira Michele, Taheri Bahman, Munoz Antonio
Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA.
Philos Trans A Math Phys Eng Sci. 2006 Oct 15;364(1847):2747-61. doi: 10.1098/rsta.2006.1851.
Owing to fundamental reasons of symmetry, liquid crystals are soft materials. This softness allows long length-scales, large susceptibilities and the existence of modulated phases, which respond readily to external fields. Liquid crystals with such phases are tunable, self-assembled, photonic band gap materials; they offer exciting opportunities both in basic science and in technology. Since the density of photon states is suppressed in the stop band and is enhanced at the band edges, these materials may be used as switchable filters or as mirrorless lasers. Disordered periodic liquid crystal structures can show random lasing. We highlight recent advances in this rapidly growing area, and discuss future prospects in emerging liquid crystal materials. Liquid crystal elastomers and orientationally ordered nanoparticle assemblies are of particular interest.
由于对称性的基本原因，液晶是软材料。这种柔软性允许长长度尺度、大的磁化率以及调制相的存在，这些调制相对外部场有很容易的响应。具有这种相的液晶是可调节的、自组装的光子带隙材料；它们在基础科学和技术方面都提供了令人兴奋的机会。由于光子态密度在禁带中被抑制而在带边处增强，这些材料可被用作可切换滤波器或无镜激光器。无序的周期性液晶结构可以表现出随机激光发射。我们重点介绍了这个快速发展领域的最新进展，并讨论了新兴液晶材料的未来前景。液晶弹性体和取向有序的纳米颗粒组装体尤其令人感兴趣。
