Index profiling of three-dimensional optical waveguides by the propagation-mode near-field method

The refractive-index profiles of a single-mode fiber and a three-dimensional waveguide are measured by the propagation-mode near-field method. This paper describes the method applied to anisotropic waveguides. The near-field pattern is observed by vidicons, and the index profile is calculated from the measured data. The light transfer characteristic of an infrared vidicon is measured and the intensity data from the infrared vidicon is corrected for the power-law response.