<title>Determination of the refractive index profile of integrated optical waveguides from near-field measurements</title>

Abstract

The refractive-index profile of optical waveguides can be obtained from transmitted near-field intensity measurements by the method of transverse offset scanning. As the calculation of the refractive-index profile from the scalar wave equation requires the second derivative of the field distribution, we developed a modified measurement setup, the modulated transverse offset scanning method.