Optical Properties of DeVries Liquid Crystals and a Look at Ultra Thin Freely Suspended Smectic Films

Liquid crystals exist as a fourth state of matter. They are anisotropic and due to this order, they affect light that passes through them, making them ideal candidates for optical study. By employing a basic technique for measuring a liquid crystal’s birefringence and tilt angle, one is able to study a number of other properties such as the electroclinic effect. In addition, smectic liquid crystals have been studied intently because of their ability to create stable ultra-thin films of quantized layer thickness. These thin films have been studied due to the fact that they are an ideal system for investigating two dimensional textures of biomembranes, hydrodynamics and interaction between inclusions. These 2D systems have been used to determine hydrodynamic properties such as mobility, viscosity, diffusions coefficients, etc [1]. This discussion will first take a look at the optical analysis that has been done on mainly DeVries liquid crystals and then continue on to describe the experimental process behind studying ultra thin freely suspended films along with some preliminary results.