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

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.