Li+ for Na+ and Na+ for Li+ Ion Exchange in Alumina Borate Glasses

In optical design, the index of refraction profile of a gradient-index element is usually expressed by a polynomial expansion. [1] Although mathematically - convenient, this type of representation cannot be constrained by manufacturing parameters during optimization. In the past, this has resulted in a trial and error fabrication process which has made the implementation of many designs difficult. A preferred method from a manufacturing standpoint would be to design the lens in terms of the actual fabrication parameters by developing diffusion models and incorporating them into a lens design program. This paper discusses a Li+-Na+ diffusion model which has been developed for an alumina borate glass system. Results of the model are compared to experimental gradient index profiles.