A study of the extraneous self-imaging phenomenon under a multimode interference configuration

Abstract

This study analyzes the phase-mismatching values of guided modes in a multimode waveguide with a weak-guiding configuration. In addition, a previously undefined self-imaging phenomenon, referred to herein as the extraneous self-imaging (Ex-SI) phenomenon, was found to result from the modal phase-mismatching effect. The evolution principle of the Ex-SI phenomenon is theoretically verified while the results from the numerical method are compared with graphical and analytical forms of the newly suggested method. Moreover, under a specific condition, the numerical results and the analytical results are compared to analyze the evolution of the Ex-SI phenomenon.