Nonreciprocal optical routing via a magneto-optical phased array on silicon

Nonreciprocal optical devices are key components in photonic integrated circuits for light reflection blocking and routing. Most reported silicon integrated nonreciprocal optical devices to date were unit devices. To allow complex signal routing between multiple ports in photonic networks, multi-port magneto-optical (MO) nonreciprocal photonic devices are desired. In this study, we report experimental demonstration of a silicon integrated 5×5 nonreciprocal optical router based on a magneto-optical phased array. By introducing different nonreciprocal phase shifts to planar photonic waveguides, the device focuses light to different ports for both forward and backward propagation directions. The device shows designable nonreciprocal optical transmission between 5×5 ports, achieving 16 dB isolation ratio and −18 dB crosstalk.