Small diameter, high strength optical fiber

A coated optical fiber, preferably a GGP optical fiber includes an optical fiber core, and a silica cladding over the optical fiber core, to provide a silica clad core. A permanent polymeric coating forms on the silica cladding during ultraviolet radiation of a photocurable composition containing a non-hydrolyzable photoinitiator. The coated optical fiber has a diameter from about 120 microns to about 160 microns and a relative frequency distribution of at least about 85% for dynamic fatigue measurements between about 49.2×10 3 kg/cm 2 (700 kpsi) and about 63.3×10 3 kg/cm 2 (900 kpsi).