Beating thermal noise in a dynamic signal measurement by a nanofabricated cavity optomechanical sensor

Thermal fluctuations often impose both fundamental and practical measurement limits on high-performance sensors, motivating the development of techniques that bypass the limitations imposed by thermal noise outside cryogenic environments. Here, we theoretically propose and experimentally demonstrate a measure-ment method that reduces the effective transducer temperature and improves the measurement precision of a dynamic impulse response signal. Thermal noise-limited, integrated cavity optomechanical atomic force mi-croscopy probes are used in a photothermal-induced resonance measurement to demonstrate an effective tem-perature reduction by a factor of approximate to 25, i.e., from room temperature down as low as approximate to 12 K, without cryogens. The method improves the experimental measurement precision and throughput by >2x, approaching the theoret-ical limit of approximate to 3.5x improvement for our experimental conditions. The general applicability of this method to dynamic measurements leveraging thermal noise-limited harmonic transducers will have a broad impact across a variety of measurement platforms and scientific fields.