Chapter 17
Liquid Crystals for Nanophotonics
17.1 Introduction
Integrating nanotechnology and liquid crystals (LCs) opens up a new area of hybrid research, which enables the realization of novel photonic devices and displays [1–7]. A study by Yeung et al. [1] showed the possibility of using nano-structured alignment surfaces based on a random distribution of vertical and horizontal polyimide domains (inhomogeneous layer) to align LC molecules for display applications. It was observed from the experiment that if the inhomogeneity was submicron in size, then there was no visible defect in the LCD and also that the layer takes on interesting properties that can be controlled by the properties of the domains. The nano-structured alignment surfaces can provide any pretilt angles between 0° and 90° and are useful for realizing zero-bias voltage π cells and bistable bend splay displays. Another major example of the application of nanotechnology to LCDs is the addition of nanoparticles to the LC [3–7]. Depending on the optical properties of the nanoparticles, which may be metallic, semiconducting or dielectric, the LC can take on different dispersive properties.
In this chapter, carbon nanotubes and LCs are integrated together to realize novel photonic devices to exploit the drastic size difference between the LC molecules (1–2 nm) and carbon nanotubes (a few nano to micro ...