Krafczyk Courtney, Jordan Andrew N, Goggin Michael E, Kwiat Paul G
Department of Physics, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.
Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA.
Phys Rev Lett. 2021 Jun 4;126(22):220801. doi: 10.1103/PhysRevLett.126.220801.
In a quantum-noise limited system, weak-value amplification using postselection normally does not produce more sensitive measurements than standard methods for ideal detectors: the increased weak value is compensated by the reduced power due to the small postselection probability. Here, we experimentally demonstrate recycled weak-value measurements using a pulsed light source and optical switch to enable nearly deterministic weak-value amplification of a mirror tilt. Using photon counting detectors, we demonstrate a signal improvement by a factor of 4.4±0.2 and a signal-to-noise ratio improvement of 2.10±0.06, compared to a single-pass weak-value experiment, and also compared to a conventional direct measurement of the tilt. The signal-to-noise ratio improvement could reach around six for the parameters of this experiment, assuming lower loss elements.
在量子噪声受限系统中，对于理想探测器，使用后选择的弱值放大通常不会比标准方法产生更灵敏的测量结果：由于后选择概率小导致功率降低，增加的弱值被抵消。在此，我们通过实验展示了利用脉冲光源和光开关进行的循环弱值测量，以实现对镜面倾斜的近乎确定性的弱值放大。与单次通过弱值实验以及传统的倾斜直接测量相比，使用光子计数探测器，我们展示了信号提高了4.4±0.2倍，信噪比提高了2.10±0.06。假设元件损耗更低，对于本实验的参数，信噪比提高可达约6。
