High-performance metal-clad multimode interference devices for low-index-contrast material systems

Metal cladding is proposed for enhancing performance of multimode interference (MMI) devices for low-index-contrast material systems and numerically investigated by the beam propagation method (BPM). Metal-cladding eliminates spurious phase errors due to the Goos-Hahnchen shift and thus yields improved imaging. The application of this concept is demonstrated by the simulation of a 1/spl times/8 MMI-based wavelength router using a typical low-index-contrast polymer channel waveguide and the results show that the crosstalk is significantly improved.