CONSTRUCTION OF REFRACTIVE-INDEX PROFILES OF GRADED-INDEX PLANAR WAVEGUIDES FROM EFFECTIVE INDEXES MEASURED WITH DIFFERENT MODE TYPES AND EXTERNAL REFRACTIVE INDEXES

摘要

A method is presented whereby the refractive-index profile (RIP) can be reconstructed from sets of effective indexes measured with different mode types and external refractive indexes. Single-mode waveguide RIP characterization can be easily realized using an index-matching liquid at a single wavelength. This method is described and demonstrated via numerical examples and experimental results. The method has the advantages of convenient operation and accurate results for the characterization of graded-index planar waveguides that support both mode types and contain known modal birefringence.