摘要 |
Gradient refractive index fibers or rods are formed of leachable glass clad glass core preforms drawn to a desired diametral size, bundled together, fused under high compressing forces and rapidly interdiffused at a temperature above their deformation point. Cooling, annealing and separation of the fibers or rods by leaching provides the end product devices which may be cut into lengths required for the lens power desired and end polished. The refractive index gradient is produced by interdiffusion of T1+ and K+ ions between core and cladding glasses which are selected to contain substantial proportions of thallium oxide and potassium oxide respectively. |