A composite polymer fiber comprises a polymer filler material and a plurality of polymer scattering fibers disposed within the filler material. At least one of the filler material and the scattering fibers is formed of a birefringent material. The refractive indices of the filler material and the scattering...http://www.google.es/patents/US7386212?utm_source=gb-gplus-sharePatente US7386212 - Polymer photonic crystal fibers
