Optical polymer thin films with isotropic and anisotropic nano-corrugated surface topologies

Light reflection from computer monitors, car dashboards and any other optic al surface can impair the legibility of displays, degrade transmission of o ptical components and in some cases may even pose safety hazards. Antirefle ctive coatings are therefore widely used, but existing antireflection techn ologies often perform suboptimally or are expensive to implement. Here we p resent an alternative approach to antireflection coatings, based on an exte nsion of our photo-aligning and photo-patterning technology for liquid-crys tal displays(1,2) (LCDs) and liquid-crystal polymer films with smooth surfa ces(3,4) to optical polymer films with controlled surface topologies. Nano- and micro-corrugated topologies are shown to result from optically induced monomer phase-separation on the polymer surfaces. The properties of the re sulting films make them suitable high-performance and low-cost antireflecti on coatings for optical components of virtually any size, shape and materia l. Moreover, the approach can be used to form a wide range of other functio nal polymer thin films with isotropic as well as anisotropic topologies. Fo r example, films can be produced whose optical birefringence exceeds that o f the birefringence of the polymer material itself. These new films can als o be used as diffractive thin films, diffusers, and directional reflectors which preserve light polarization, or as substrates for aligning liquid cry stals to produce bright, low-power-consumption LCDs with integrated optical functions and memory.