微纳机械振子在精密测量领域有着广泛的应用,其中调幅或者调频技术是机械振子力 学探测中常用的两种方法。一般情况下机械振子测量灵敏度主要受到热噪声的限制。因此,采用压缩的方法来降低特定相应 测量分量上的热噪声可以有效提高微纳机械振子的力学测量灵敏度。在腔光力系统中通过锁相环路锁定机械振子的振动频率, 并利用光学囚禁对机械振子的振动频率进行调制,在调制频率为机械振子共振频率的两倍时成功对机械振子的特定振动分量进 行了压缩。并且通过反馈增强系统稳定的方法,成功地超越了参量压缩的3 dB极限,达到了4.4 dB的最大压缩率。

Micromechanical resonator is widely used in accurate measurements, in which frequency modulation and amplitude modulation are two usually used techniques. Generally, the force sensitivity of mechanical resonator is mainly limited by the thermal noise. Therefore, reducing the thermal noise of measurement quadrature by squeezing the mechanical resonator can effectively improve the sensitivity of the mechanical resonator. By using a phase lock loop to lock the resonator’s vibration frequency, a specified motion quadrature of mechanical resonator is squeezed when the frequency of the mechanical resonator is modulated at twice of its resonant frequency by using an optical trap. By using a feedback loop to stabilize the measurement system, 3 dB limit of the parametric squeezing is successfully overcome and a max squeezing rate about 4.4 dB is achieved.