Analysis of coupled rib and buried waveguides for efficient mode-spot converters

Abstract

A novel spectral method, which combines the advantages of two proven techniques, namely the Spectral Index and Free Space Radiation Mode methods, is presented for the analysis of a mode spot converter with air clad boundaries. The approach is very efficient and accurate, giving propagation constants and field proffles in a matter of seconds. Design curves and field profiles which can be used to optimise the spot converter are also given.