Measurement of optical refractive index profiles

摘要

To determine the radial profile of the refractive index of a substantially cylindrical transparent object such as an optical fibre or optical fibre preform, the object is illuminated with a collimated beam of light incident at an angle to the axis of the cylindrical object differing substantially from 90 degrees and measuring the refraction angle at which light leaves a substantially plane endface as a function of the radial position on the endface.