摘要 |
<p>An optical element, consisting essentially of an amorphous compound and having a refractive index which varies throughout the element, is prepared by introducing a melt of the material into a mold and cooling it in such a manner that the material gradually solidifies, while simultaneously applying a programmed pressure to the cooling melt. When the material is fully solidified, it possesses a refractive index gradient. An element manufactured by this method has a capacity for guiding and focusing light.</p> |