High-speed high-resolution fiber diameter variation measurement system.

A fiber diameter variation measurement system is described which is capable of measuring transparent fibers with 0.02% diameter resolution and 6-microm axial resolution at a measurement rate of 1 kHz and with a working distance of >100 mm. The principles of its operation are discussed in detail, and experimental confirmation of its performance is reported. A theoretical calculation of the optimum obtainable diameter resolution for a given set of experimental parameters is also presented.