Single-Mode Refractive Index Reconstruction Using an NM-Line Technique

Abstract

A new technique for the measurement of single-mode planar waveguide refractive index profile is developed. This technique, based on the successive etching and effective index measurement, is applied on planar guides fabricated on a glass substrate using K+-Na+ ion exchange where the guide is etched using diluted HF acid and the mode effective index is measured by the well-known M-lines technique. The profile measured by this technique is assisted by modal calculations using a numerical mode solver and a strong agreement is obtained.