Gupta Prasoon, Schmittberger Bonnie L, Anderson Brian E, Jones Kevin M, Lett Paul D
Opt Express. 2018 Jan 8;26(1):391-401. doi: 10.1364/OE.26.000391.
Homodyne detection is often used for interferometers based on nonlinear optical gain media. For the configuration of a seeded, "truncated SU(1,1)" interferometer Anderson, et al. [ Phys. Rev. A95, 063843 (2017)] showed how to optimize the homodyne detection scheme and demonstrated theoretically that it can saturate the quantum Cramer-Rao bound for phase estimation. In this work we extend those results by taking into account loss in the truncated SU(1,1) interferometer and determining the optimized homodyne detection scheme for phase measurement. Further, we build a truncated SU(1,1) interferometer and experimentally demonstrate that this optimized scheme achieves a reduction in noise level, corresponding to an enhanced potential phase sensitivity, compared to a typical homodyne detection scheme for a two-mode squeezed state. In doing so, we also demonstrate an improvement in the degree to which we can beat the standard quantum limit with this device.
零差检测常用于基于非线性光学增益介质的干涉仪。对于种子注入的“截断SU(1,1)”干涉仪的配置，安德森等人[《物理评论A》95, 063843 (2017)]展示了如何优化零差检测方案，并从理论上证明了它可以使相位估计的量子克莱姆 - 罗奥界饱和。在这项工作中，我们通过考虑截断SU(1,1)干涉仪中的损耗并确定用于相位测量的优化零差检测方案来扩展这些结果。此外，我们构建了一个截断SU(1,1)干涉仪，并通过实验证明，与双模式压缩态的典型零差检测方案相比，这种优化方案实现了噪声水平的降低，对应于增强的潜在相位灵敏度。在此过程中，我们还展示了使用该装置在超越标准量子极限程度上的改进。
