Evaluation of fiber slippage and core-axis offset distribution in optical fiber mechanical splice

When fibers are clamped together between two fiber-holding substrates and butt-joined, variations in the fabrication accuracy of both fibers and substrates usually result in the fibers experiencing different clamping forces. If, for example, a couple of fibers are undersized or the substrate surface is deformed, the clamping force will be insufficient in places. In such cases, the fibers will leave only faint linear marks on the substrate surface and may slip when internal or external forces act on them. By using Hertz's theory, we converted the resistance force to fiber slippage into a line width curve for the onset of slippage. We spliced single fibers with known outer diameters to examine the influence of line width on slippage. We performed a fiber retention test, a temperature cycling test to determine any insertion loss change, and observed the linear marks with a microscope. No fiber slippage occurred when the width of the linear marks was outside the line width curve. Furthermore, we calculated the core-axis offset probability distribution when the optical fiber axes were aligned.