the technique for measuring the refractive index profile of an optical fibre by scanning the entrance face with the vertex of a high numerical aperture cone of monochromatic light and measuring the change in power of refracted rays Found on http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=731-07-13
the technique for measuring the refractive index profile of an optical fibre by scanning the entrance face with the vertex of a high numerical aperture cone of monochromatic light and measuring the change in power of refracted rays