Spherical gradient-index sphere lens.

The sphere lens with a spherical gradient-index (GRIN) was prepared for the first time by two modified suspension polymerization techniques. The index change of the 0.05–3.0-mm diam GRIN sphere was 0.02–0.04, and the index profile was almost quadratic. The optimum condition minimizing the spherical aberration of the GRIN sphere embedded in a certain substrate was confirmed. Furthermore, 1-D and 2-D GRIN sphere lens arrays were fabricated.