Graded index lens for fiber optic applications and technique of fabrication

摘要

A non-phase separable glass material for fabricating a GRIN lens comprises 5-20 mole % boron oxide and ratio R of network modifiers in mole % to the network former boron oxide in mole % is in the range of about 1-1.5. The melted preform of such glass material is extruded through an opening to form a glass rod where the extrusion process eliminates bubbles that may be present in the preform. Neodymium oxide may be added in the frit material for forming the preform to reduce friction forces in the extrusion process and reduces the stress in the glass rod. Centerless grinding may be performed to control the diameter and roughness of the surface of the rod to control the diffusion parameters during the subsequent ion-exchange.