Non‐Volatile Hybrid Optical Phase Shifter Driven by a Ferroelectric Transistor

Abstract Optical phase shifters are essential elements in photonic integrated circuits (PICs) and function as a direct interface to program the PICs. Non‐volatile phase shifters, which can retain information without a power supply, are highly desirable for low‐power static operations. Here a non‐volatile optical phase shifter is demonstrated by driving a III‐V/Si hybrid metal‐oxide‐semiconductor (MOS) phase shifter with a ferroelectric field‐effect transistor (FeFET) operating in the source follower mode. Owing to the various polarization states in the FeFET, multistate non‐volatile phase shifts up to 1.25π are obtained with CMOS‐compatible operation voltages and low switching energy up to 3.3 nJ. Furthermore, a crossbar array architecture is proposed to simplify the control of non‐volatile phase shifters in large‐scale PICs and verify its feasibility by confirming the selective write‐in operation of a targeted FeFET with a negligible disturbance to the others. This work paves the way for realizing large‐scale non‐volatile programmable PICs for emerging computing applications such as deep learning and quantum computing.