Silicon integrated nonreciprocal photonic devices using monolithically integrated magnetic oxides

In this work, we report our recent progress on monolithic integration of magneto-optical oxide thin films and nonreciprocal photonic devices on silicon. We demonstrate strong Faraday rotation of − 6000 deg/cm at 1550 nm wavelength in silicon integrated Ce 1.5 Y 1.5 Fe 5 O 12 films, which exceeds the Faraday rotation of epitaxial CeiY 2 Fe 5 Oi 2 thin films on garnet substrates. We also present the design of a broadband optical isolator using silicon/CeYIG/silicon MMI structure. The device shows 20 dB isolation bandwidth of 1.6 nm, and insertion of 0.817 dB at 1550 nm wavelength, with a very compact device footprint of 310.42 μm. The fabrication tolerance and influence of a YIG seed layer on the device performance are also discussed.