... 10 ≤ r ≥25 Curvature eccentricity um <50 Fiber core undercut nm <50 Insertion loss change< 0.1, ... 10 ≤ r ≥25 Curvature eccentricity um <50 Fiber core undercut nm <50 Insertion loss change< 0.1, ... < 0.2. Use: Applied in optical fiber communications system, fiber optic data transmission, LAN, optical fiver sensors ... ≥ 60 5 Curvature eccentricity um <50 6 Fiber core undercut um - <50 7 Fall apart test dB ...