论文标题
通过播种增强非线性干涉法
Enhanced nonlinear interferometry via seeding
论文作者
论文摘要
在存在内部损失和效率低下的探测器的情况下，我们分析了非线性干涉仪，也称为SU（1,1）干涉仪。为了克服这些局限性，我们考虑了用数量状态或相干状态播种的一种干涉仪输入模式之一的效果。我们为干扰可见性，对比度，相位灵敏度和信噪比提供了分析表达式，并显示出所有这些数量的显着增强，这与播种光子数的函数相关。例如，我们预测，即使存在大量损失和高效率探测器，我们也可以通过与几十个光子播种来实现未种子非线性干涉仪的相同量子限制相位灵敏度。此外，当干涉仪以低增生状态运行时，我们观察到数字或相干播种状态之间没有差异，这可以通过减弱的激光播种。我们的结果扩大了在现实的实验条件下量子成像，计量学和光谱领域中的非线性干涉仪能力。
We analyse a nonlinear interferometer, also known as an SU(1,1) interferometer, in the presence of internal losses and inefficient detectors. To overcome these limitations, we consider the effect of seeding one of the interferometer input modes with either a number state or a coherent state. We derive analytical expressions for the interference visibility, contrast, phase sensitivity, and signal-to-noise ratio, and show a significant enhancement in all these quantities as a function of the seeding photon number. For example, we predict that, even in the presence of substantial losses and highly inefficient detectors, we can achieve the same quantum-limited phase sensitivity of an unseeded nonlinear interferometer by seeding with a few tens of photons. Furthermore, we observe no difference between a number or a coherent seeding state when the interferometer operates in the low-gain regime, which enables seeding with an attenuated laser. Our results expand the nonlinear interferometry capabilities in the field of quantum imaging, metrology, and spectroscopy under realistic experimental conditions.
