High-sensitivity and wide-dynamic-range parameter estimation via weak-value amplification

In sensing technologies, the efforts for increasing sensitivity are usually at the cost of restraining the dynamic range. Here, we propose a closed-loop-control-based weak-value amplification (WVA) method to address this trade-off problem. Different from the previous adaptive WVA schemes, our method can significantly increase the dynamic range without sacrificing sensitivity, and hence improve the sensing dynamic factor by several orders of magnitude, in principle. Moreover, by employing the small weak value in the feedback process, the phase-modulation uncertainty can be effectively suppressed and provide much higher SNR in practice. Additionally, our approach achieves high-sensitivity detection and high-precision closed-loop control on two distinct dimensions within the same weak-measurement system. Our method can find broad applications on sensing technologies that require both high sensitivity and wide dynamic range, such as the sensing of temperature, magnetic fields, pressure, angular velocity, and so on.