论文标题
多光子吸收的量子增强测量值的非线性干涉法
Nonlinear Interferometry for Quantum-Enhanced Measurements of Multiphoton Absorption
论文作者
论文摘要
在许多光谱，微观或光刻应用中，多光子的吸收至关重要。但是，鉴于它是一个固有的弱过程，因此多光子吸收信号的检测通常需要大的场强度，从而阻碍其在许多实际情况下的适用性。在这项工作中，我们表明，将多光子吸收剂放入不平衡的非线性干涉仪内，可以增强基于连贯甚至挤压光的直接传输测量的策略，相对于策略的策略相对于策略提高了多光子的能量。特别是，与样品的传输测量相比，可以通过一致的光线来增加对光子通量的敏感性的功率缩放，这意味着可以在大幅降低的激发强度下观察到信号。此外，我们表明，这种增强的测量精度与导致光子损失的实验瑕疵具有鲁棒性，通常会降低检测灵敏度。我们将这种增强的起源追踪到最佳的挤压程度，该挤压必须在非线性SU（1,1） - 接入计中生成。
Multiphoton absorption is of vital importance in many spectroscopic, microscopic or lithographic applications. However, given that it is an inherently weak process, the detection of multiphoton absorption signals typically requires large field intensities, hindering its applicability in many practical situations. In this work, we show that placing a multiphoton absorbent inside an imbalanced nonlinear interferometer can enhance the precision of multiphoton cross-section estimation with respect to strategies based on direct transmission measurements by coherent or even squeezed light. In particular, the power scaling of the sensitivity with photon flux can be increased by an order of magnitude compared to transmission measurements of the sample with coherent light, meaning that a signal could be observed at substantially reduced excitation intensities. Furthermore, we show that this enhanced measurement precision is robust against experimental imperfections leading to photon losses, which usually tend to degrade the detection sensitivity. We trace the origin of this enhancement to an optimal degree of squeezing which has to be generated in a nonlinear SU(1,1)-interferometer.
