Microgravity processing of polymets for NLO applications

Crystals grown in space have been shown to be of higher quality than “earth-grown” crystals because more defect-free specimens are obtained in the absence of gravity-fueled convection. Defect-free organic crystals are of particular interest because they can exhibit high optical nonlinearities. However, they tend to be brittle and cannot be as easily fabricated into thin films or fibers. Polymers having a controlled supramolecular structure and morphology could be even more promising candidates as NLOM. Our previous NASA work supported the rationale for orienting biopolymers, materials with known supramolecular structure, in an electric field under microgravity conditions in order to optimize optical χ2 non-linearity; the magnitude of the NLO response was directly related to the degree of molecular order within the film. Other related work has demonstrated the potential for processing of χ3 materials such as sols, porphyrins and fullerenes in inert polycarbonate (PC) polymer matrices. Our Phase II SBIR wor...