Gradient-index polymer rods and fibers

摘要

The invention features a method of making a gradient-index polymer rod involving the steps of: combining a polymer with an additive, wherein the refractive index of the polymer material is different than the refractive index of the additive material; extruding the polymer and the additive into a polymer rod having a substantially uniform index of refraction profile; and immersing the rod having the substantially uniform index of refraction profile in a non-solvent under conditions and for a time that enables the non-solvent to permeate the rod and out-diffuse a portion of the additive material, thereby producing the gradient-index polymer rod. The rod produced by the method can be drawn into a graded index polymer fiber. The invention also features a gradient-index polymer rod (or fiber) of condensation-type polymer that is doped with an additive material. The refractive index of the additive material is different than the refractive index of the polymer and the rod (or fiber) has a concentration profile of the additive that varies along the radial direction of the rod (or fiber) from the center to the surface of the rod (or fiber).