Superconducting optomechanical circuits enable frequency mixing of optical and mechanical modes,facilitating the generation of microwave frequency combs.However,such optomechanical combs suffer from frequency fluctuat...Superconducting optomechanical circuits enable frequency mixing of optical and mechanical modes,facilitating the generation of microwave frequency combs.However,such optomechanical combs suffer from frequency fluctuations,requiring their stabilization for applications in precision sensing and signal processing.Here,we investigate the sideband injection locking of microwave frequency combs in a niobium-based superconducting optomechanical circuit.By strongly driving the device with a blue-detuned pump to induce parametric instability and introducing an additional tone near individual comb peaks,we study how the locking range varies with the power,the frequency position,and the sweep direction of the injection tone.The locking responses show interesting features such as injection hysteresis,which cannot be explained by existing models.Numerical simulations of the classical optomechanical equations implementing a cubic mechanical nonlinearity show that the nonlinearity contributes to broadening the locking range.We also characterize the Allan deviations and phase noise of the injection-locked combs for different injection frequencies,demonstrating enhanced stability performance.Our results lay the foundation for the utilization of optomechanical combs for applications in nanomechanical sensing and cryogenic microwave pulse generation.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant(RS-2022-NR072112)the National Research Council of Science&Technology(NST)grant(No.CAP21034-000)+1 种基金Institute for Information&Communications Technology Planning&Evaluation(IITP)grant(No.RS-2025-02219093)the Korea Research Institute of Standards and Science(GP2025-0010-03)funded by the Korea government(MSIT).
文摘Superconducting optomechanical circuits enable frequency mixing of optical and mechanical modes,facilitating the generation of microwave frequency combs.However,such optomechanical combs suffer from frequency fluctuations,requiring their stabilization for applications in precision sensing and signal processing.Here,we investigate the sideband injection locking of microwave frequency combs in a niobium-based superconducting optomechanical circuit.By strongly driving the device with a blue-detuned pump to induce parametric instability and introducing an additional tone near individual comb peaks,we study how the locking range varies with the power,the frequency position,and the sweep direction of the injection tone.The locking responses show interesting features such as injection hysteresis,which cannot be explained by existing models.Numerical simulations of the classical optomechanical equations implementing a cubic mechanical nonlinearity show that the nonlinearity contributes to broadening the locking range.We also characterize the Allan deviations and phase noise of the injection-locked combs for different injection frequencies,demonstrating enhanced stability performance.Our results lay the foundation for the utilization of optomechanical combs for applications in nanomechanical sensing and cryogenic microwave pulse generation.
