Surface Plasmon Enhanced Integrated Optical Isolator

Integrated photonics offer the promise of combining many optical devices on a substrate, leading to miniaturization and increased functionality on a chip. Isolators are critical elements for optical systems, since backscattered light creates noise and laser source instability, particularly in integrated platforms where the potential for backscattering increases with device density. Despite the need for integrated optical isolators, practical realization of such devices is challenging due to the lattice mismatch between materials, such as yttrium iron garnet (YIG), utilized to fabricate bulk magneto-optic isolators and materials, typically InP or GaAs, used for photonic chips. To address this need, we propose to design, model, and demonstrate an optical isolator capable of producing <3dB insertion loss and >30dB isolation that can be integrated with standard III-V semiconductor materials. Our approach exploits the known property of surface plasmons waveguides to enhance the magneto-optic response in a magnetically doped III-V semiconductor.