| This dissertation is focused on the synergistic combination of the nanostructured architectures of coextruded multilayered polymer films and tailored functional additives to create novel and useful functional optical material systems. Layer multiplying coextrusion was used to create layered polymeric systems with hundreds to thousands of layers with individual layer thicknesses in the range of 90 nm to 20 mum. If transparent polymers of different refractive index are employed, these films can display characteristics of one dimensional photonic crystals whose reflection and transmission characteristics can be readily tailored via the geometry and refractive indices. The experiments shown in this thesis demonstrate that the functionality and range of possible applications for these layered polymeric systems can be greatly expanded through incorporation of functional additives, which can take the form of nanoparticles, small organic species, and tailored polymers. Thus, properties such as refractive index, fluorescence, sensing ability, stimuli responsiveness, and optical upconversion were controlled in multilayered films using a variety of polymer hosts and functional additives. These components were united to develop a number of technologically relevant optical systems including terahertz photonic crystals, all-polymer distributed Bragg reflector and distributed feedback lasers, stimuli responsive mechanochromic sensors, materials for three dimensional optical data storage, and the first and a number of subsequent solid-state optical upconversion systems. The combination of fabrication methods which are amenable to rapid, inexpensive, large-scale industrial production with materials performance that is competitive with current state of the art systems in a number of high-tech applications means the concepts explored herein should have an ever expanding impact in years to come. |
