Nanocomposites with very large electro-optic effect and widely tunable refractive index

A very large electro-optic effect has been observed in relaxor ferroelectric poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer. By adding a small amount of zinc sulfide nanoparticles, the refractive index of the nanocomposite can be tuned between 1.4 and 1.5 while retaining a large electro-optic effect and high transparency. Tunable long-period fiber gratings have been fabricated with the polymer nanocomposite as the second cladding, and a resonance wavelength shift of over 50nm has been achieved when electric field changed by 30V∕μm. This magnitude of shift corresponds to pure refractive index change of Δn∕n≈0.4% in the nanocomposite.