Grating Coupler Enabled Optical Isolators and Circulators for Photonic Integrated Circuits

A novel concept for an integrated optical isolator is proposed and theoretically validated using realistic parameters. Simulated insertion loss is 5.7 dB and optical 1-dB bandwidth is 14 nm. An isolation extinction ratio of over 20 dB is shown to be feasible. The compatibility with existing foundry processes for photonic integration, the small footprint and the tolerant integration approach make this a promising candidate for on-chip isolators. It is further shown that the concept can be used as an on-chip optical circulator.