Wavelength routers for multilayer integrated optical networks on chip

The design and analysis of grating-assisted vertical couplers, which behave as add-drop filters, is proposed for routing the signal among the different layers of a multilayer optical network. Simple design criteria are found based on the mode analysis and demonstrated by the Finite Difference Time Domain (FDTD) simulations. The device can be used in multilayer networks to implement add-drop filters or multiplexers/demultiplexers. Moreover, it can be regarded as a 2×2 wavelength router which can be assembled in higher-order three-dimensional matrices to achieve wavelength routing in integrated multilayer networks.