To control thermo-optic (T-O) coefficient of polymer materials, hybrid polymer system with inorganic nanoparticles
was examined. Polymer materials have high T-O coefficient but low refractive index. On the other hand, inorganic
materials have low T-O coefficient but high refractive index. Then surface treated inorganic nanoparticles were dispersed
into epoxy polymers. By increasing inorganic nanoparticle contents, refractive index of hybrid polymer changed and its
T-O coefficient decreased.