ROBUST REGRESSION APPLIED TO OPTICAL-FIBER DIMENSIONAL QUALITY-CONTROL

To minimize coupling losses when low-cost connectors are used to mate optical fibers, manufacturers need to maintain tight control of fiber dimensions. The video-microscope, or gray-scale, method is the most fr equently used technique on the manufacturing Boor for measuring the ge ometric parameters of the cleaved end of a telecommunications fiber. W e present a method for performing optical-fiber dimensional quality co ntrol that allows for end face damage and accounts for the special str ucture of measurement errors in fiber edge points; calculated from gra y-scale images. The new approach adheres to the industrial standard te st procedure by fitting an ellipse to the edge table to obtain geometr ic measurements. But, to create high-breakdown resistance to outliers, a data filter based on the least median of squares criterion is used.