Ferrofluids, sol-gel method and materials for optical applications

237-240This paper describes how ferrofluids can be used to develop new composite materials for optical applications. Ferrofluids are interesting materials for optics. Isotropic in a zero magnetic field, these hybrid media exhibit optical anisotropies under an applied magnetic field. For optical applications, the drawback of ferrofluids is their liquid state. It is shown that by using sol-gel method new solid material can be achieved. Moreover, permanent linear birefringence has been obtained for sol-gel samples synthesized under an applied field. This anisotropy can be adjusted. Doped sol-gel structures keep the same magneto-induced circular anisotropy of the ferrofluid but no permanent effect is achieved