MEASUREMENTS OF A SEMICONDUCTOR WAVE-GUIDE USING A LOW-COHERENCE INTERFEROMETRIC REFLECTOMETER

A low-coherence interferometric reflectometer is studied as a tool to measure both semiconductor waveguide loss and reflectivity, Accurate e stimation is given by using the integral values of the interference en velopes observed as reflected power from the sample. This estimation i s free of influence from coupling between the sample and reflectometer or dispersion in the semiconductor materials. The experimental result s are in good agreement with those obtained by the Fabry-Perot method. The facet reflectivity measured in 0.5-mm-long very short samples sho ws waveguide thickness dependence agrees with theoretical results, Thi s approach shows good repeatability and accuracy for short samples.