A CALCULATION OF THE CENTER WAVELENGTH IN WAVE-GUIDE DIRECTIONAL-COUPLERS

This short communication addresses the issue of the different calculations of the center wavelength of non-identical waveguide couplers by the traditional coupled-mode theory and other improved models, which has been raised in recent studies. It attempts to clarify the significance and device performance consequences of the accuracy of the center wavelength calculation. The analysis is based on a supermode theory.