Fig. 4. Dependence of the radial nickel thickness profiles of five probes on the cross-sectional diameter of fiber. Here, curve A0 and curve A1 corresponds to the profiles of probes A0 and A1 as appeared in Fig. 2(b). For curves B0–B2, the nickel plating solution with a temperature of 60 ℃ was agitated by the ultrasonic wave with power densities of 0, 1.6, and 2.2Wcm-2, respectively. The plating times of the five probes is 15 min.