Refracted-Ray Scanning (Refracted Near-Field Scanning) for Measuring Index Profiles of Optical Fibers

摘要

The purpose of this work is twofold. First, it provides an elementary description and tutorial overview of the new refracted-ray method of measuring fiber-index profiles. Second, it presents new results concerning the theoretical foundation, the linearity and precision, resolution limit and edge response, and other aspects of the method. In particular it was found that index differences may be measured to 5 percent or better and spatial resolution is diffraction limited. The author concludes by showing about 3 percent agreement with another laboratory, and good agreement with numerical-aperture measurements performed by participants in a round-robin experiment.