Abstract
A nonhomogeneous medium is one in which the refractive index varies from point to point within the medium. Currently the term "gradient index" (GRIN) is often used to describe such medium. The possibility of using this medium in man-made optical instruments has been considered for many years, but now it has been possible to fabricate the appropriate materials to exploit this idea. Many researches have been devoted not only to theoretical developments in this field, but also to improved methods of producing and measuring the necessary materials. The communication industry has been developing the use of GRIN fibers as a highly efficient means of transporting information. Light loss in GRIN fiber tend to be very low, since rays within this fiber are curved in such a way they are not reflected at the fiber surfaces.
