DETAILING SMECTIC SSFLC DIRECTOR PROFILES BY HALF-LEAKY GUIDED MODE TECHNIQUE AND GENETIC ALGORITHM

The genetic algorithm (GA), written to allow automatic analysis of opt ical reflectivity data obtained from liquid crystal cells using the ha lf-leaky guided mode technique, has been developed to the point where liquid crystal cells can be analysed successfully giving greater detai l of optical parameters and director profile than yielded by any other technique. The technique models the liquid crystal layer as a set of discrete, independent sub-layers which can map out the variation of th e director through the thickness of the cell. Given sufficient high qu ality data, it is now possible automatically and accurately to ht the parameters of a complete liquid crystal cell. Using this highly adapte d GA, half-leaky guided mode optical reflectivity data from the nemati c, smectic A and smectic C* phases of SCE13 in a surface stabilized fe rroelectric liquid crystal have been fitted to reveal director profile s and optical parameters of the cell in each phase.