Patterned optical properties in photopolymerized surface-aligned liquid-crystal films

Abstract

MOST practical applications of liquid crystals require control of molecular alignment at macroscopic scales¹. This is achieved most simply by confining the liquid-crystalline phase between mechanically rubbed surfaces¹. Recent developments^2–11 have shown that liquid-crystal alignment can also be controlled by optical means: for example, if azo dyes either on the alignment surface^2,3,5,8–11 or dispersed within the liquid crystal itself^4,6,7 are oriented by illumination with polarized light, alignment can be induced in the liquid crystal. We show here that the high-resolution alignment patterns obtainable by such techniques may be 'frozen in' by subsequent photopolymerization of the optically patterned liquid-crystalline phase. The resulting polymer films might prove valuable in the development of high-density optical storage media, three-dimensional stereo displays and other optical devices.