Microring-based Optical Isolator and Circulator with Integrated Electromagnet for Silicon Photonics
In this study, we present optical isolators and circulators fabricated by bonding cerium-substituted yttrium iron garnet (Ce:YIG) on silicon microring resonators. A novel integrated electromagnet is fabricated by depositing a metal micro-strip on the bonded chip. We experimentally prove that it can be efficiently used to control the magnetic field needed to induce the nonreciprocal phase shift effect in the Ce:YIG. The fabricated devices exhibit extremely small footprint (≤ 70 μm) and can be packaged, eliminating the need of a large size permanent magnet.