Preparation of graded-index optical glass fibres in the alkali germanosilicate system

Abstract

Multicomponent glass fibres with a graded refractive index have been made in the alkali germanosilicate system using the double-crucible method. The index profile is based on Na+ ⇌ K+ ion exchange. Bulk-glass absorption losses of ≤10 dB/km at 752 nm have been measured. The present minimum level of fibre attenuation is 35 dB/km.