Cavity modulator assisted nonreciprocal light transmission on Silicon

Nonreciprocal light transmission is indispensable in many photonic circuits. It forms the basis of optical isolators, which allow the propagation of light in a specific direction while blocking the propagation in the opposite direction [1] . When placed after a laser, an optical isolator inhibits back-reflections in the laser and also alleviates multipath interference [2] . There are three major methods to achieve non-reciprocal optical transmission i.e. modulation, depositing magneto-optic materials, and non-linear effects. The modulation based approach has the potential to deliver high isolation and offers seamless integration with existing silicon photonic integrated circuit components [3] .