Ganesan Adarsh, Seshia Ashwin
Nanoscience Centre, University of Cambridge, Cambridge, UK.
Sci Rep. 2019 Jul 1;9(1):9452. doi: 10.1038/s41598-019-46003-3.
Micro and nanomechanical resonators have been extensively researched in recent decades for applications to time and frequency references, as well as highly sensitive sensors. Conventionally, the operation of these resonant sensors is implemented using a feedback oscillator to dynamically track variations in the resonant frequency. However, this approach places limitations on the frequency stability of the output response, particularly owing to near-carrier noise shaping, limiting measurement stabilities at short-to-moderate integration times. Here, in this paper, utilizing the recent experimental demonstration of phononic frequency combs, we demonstrate an alternative resonance tracking approach with the potential to provide significant improvements in near-carrier phase noise and long-term stability. In addition, we also showcase comb dynamics mediated resonant frequency modulation which indirectly points to the possible control of inevitable noise processes including thermomechanical fluctuations. This resonant tracking approach may also have general applicability to a number of other physical oscillators.
近几十年来，微纳机械谐振器在时间和频率基准以及高灵敏度传感器方面得到了广泛研究。传统上，这些谐振传感器的操作是通过反馈振荡器来动态跟踪谐振频率的变化。然而，这种方法对输出响应的频率稳定性有一定限制，特别是由于近载波噪声整形，在短至中等积分时间内限制了测量稳定性。在此，本文利用最近声子频率梳的实验演示，展示了一种替代的谐振跟踪方法，该方法有可能在近载波相位噪声和长期稳定性方面带来显著改善。此外，我们还展示了梳状动力学介导的谐振频率调制，这间接表明了对包括热机械波动在内的不可避免噪声过程的可能控制。这种谐振跟踪方法也可能广泛适用于许多其他物理振荡器。
