H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom.
Phys Rev Lett. 2010 Jul 2;105(1):010405. doi: 10.1103/PhysRevLett.105.010405.
Recently, weak measurements were used to measure small effects that are transverse to the propagation direction of a light beam. Here we address the question of whether weak measurements are also useful for measuring small longitudinal phase shifts. We show that standard interferometry greatly outperforms weak measurements in a scenario involving a purely real weak value. However, we also present an interferometric scheme based on a purely imaginary weak value, combined with a frequency-domain analysis, which may have the potential to outperform standard interferometry by several orders of magnitude.
最近，弱测量被用于测量与光束传播方向横向上的小效应。在这里，我们探讨了弱测量是否也可用于测量小的纵向相移。我们表明，在仅涉及实的弱值的情况下，标准干涉测量比弱测量优越得多。然而，我们还提出了一种基于纯虚的弱值的干涉测量方案，并结合频域分析，这可能有潜力使标准干涉测量的性能提高几个数量级。
