Preparation of long lengths of ultra-low-loss single-mode fibre

Abstract

Single-mode m.c.v.d. fibres have been prepared in lengths of up to 10 km by incorporating easily sinterable cladding layers of both boron-phosphorus-and fluorine-phosphorus-doped silica. Minimum losses of 0.6 to 0.7 dB/km have been achieved in the wavelength range 1.1 to 1.7 μm.