Ultralow‐Power Piezo‐Optomechanically Tuning on CMOS‐Compatible Integrated Silicon‐Hafnium‐Oxide Platform

Abstract Power consumption of photonic integrated circuits becomes a critical consideration. A new platform is proposed for ultralow‐power tuning in silicon photonics via piezo‐optomechanical coupling using hafnium‐oxide actuators. As an example of the potential of the platform, a tunable silicon‐hafnium‐oxide hybrid microring, where hafnium‐oxide film acts as an active optical and piezoelectric layer, is demonstrated. The hybrid microring is capable of linear bidirectional tuning with a wavelength tuning efficiency of 8.4 pm V −1 and a power efficiency of 0.12 nW pm −1 . The estimated power consumption for tuning a free spectral range (FSR) in hybrid microring is 3.07 µW per FSR. The hybrid silicon‐hafnium‐oxide technology with complementary metal‐oxide‐semiconductor (CMOS) compatibility advances the field of ultralow‐power integrated photonic devices and can find applications in optical communications, computing, and spaces under cryogenic temperatures.