Patent ID: 8295666

Claim:
A coated optical fiber comprising: a glass fiber coated by at least two coating layers, the at least two coating layers including a soft layer and a hard layer, wherein the at least two coating layers are made from an ultraviolet-curable resin, and the ultraviolet-curable resin of the soft layer includes oligomer which produces one of C 3 H 7 O+ (m/z 59) or C 4 H 9 O+ (m/z 73) peaks in cation analysis of Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), and the glass surface of the glass fiber, where the at least two coating layers of the coated optical fiber are removed, has a peak intensity ratio of 0.6 or more in one of C 3 H 7 O+ (m/z 59) and C 4 H 9 O+ (m/z 73) peaks with respect to Si+ (m/z 28) peak in cation analysis of TOF-SIMS.