A nano vacuum gauge based on second-order coherence in optical levitation

Accurate measurement of pressure with a wide dynamic range holds significant importance for various applications. This issue can be realized with a mechanical nano-oscillator, where the pressure-related collisions with surrounding molecules induce its energy dissipation. However, this energy dissipation of the nano-oscillator may be overshadowed by other processes. Here, we apply the second-order coherence analysis to accurately characterize those distinct dissipation processes. Based on an optically levitated nano-oscillator, we successfully obtain precise measurements of the air pressure surrounding the particles from atmosphere to 7E-6 mbar, over 8 orders of magnitude. It proves that the mechanical nano-oscillator is an extremely promising candidate for precision pressure sensing applications. Moreover, the second-order coherence analysis method on a classical system can pave the way to characterize the dynamic properties of an oscillator, which will benefit microscopic thermodynamics, precision measurement, and macroscopic quantum research.