One-way light transmission in compact SOI structures

Nonreciprocal transmission of the light is fundamental in all-optical processing systems and, it is in a great demand in advanced optical communication networks. Optical devices based on one-way light transport are essential to prevent interference between various integrated components of the optical networks. The integration of these devices in a single platform is a challenging task due to material incompatibilities between the integrated devices. We report all-silicon-on-insulator waveguides where the asymmetric light propagation is obtained. These waveguides are coupled using micro rings with modified gaps. We show that unidirectional optical transmission of the light can be accomplished by non-symmetric distribution of micro rings and gaps between the waveguides. We also show the time domain snapshot of the light propagation from left to right and from right to left behaves differently. The advantageous properties of the proposed structure are the compatibility with the integrated photonics and can serve as a main building block for designing integrated silicon nanophotonic devices.