Quantum interferometry based on induced-coherence phenomena has demonstrated the possibility of undetected-photon measurements. Perturbation in the optical path of probe photons can be detected by interference signals generated by quantum mechanically correlated twin photons propagating through a different path, possibly at a different wavelength. To the best of our knowledge, this work demonstrates for the first time a hybrid-type induced-coherence interferometer that incorporates a Mach–Zehnder-type interferometer for near-visible photons and a Michelson-type interferometer for infrared (IR) photons, based on double-pass-pumped spontaneous parametric down-conversion. This configuration enables IR optical measurements via the detection of near-visible photons and provides methods for optimizing the quality of measurements by identifying photon pairs of different origins. We theoretically identify that the induced-coherence interference visibility is approximately the same as the heralding efficiency between twin photons along the relevant spatial modes, and experimentally maximize the visibility by setting up a common reference spatial mode for IR photons. Applications to both time-domain and frequency-domain quantum optical induced-coherence tomography for three-dimensional test structures are demonstrated. The results prove the feasibility of practical undetected-photon sensing and imaging techniques based on the presented structure.

中文翻译：

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混合干涉仪的量子光学诱导相干断层扫描

基于诱导相干现象的量子干涉测量已经证明了未检测到的光子测量的可能性。探测光子光路中的扰动可以通过量子力学相关双光子产生的干涉信号来检测，这些干涉信号通过不同的路径（可能以不同的波长）传播。据我们所知，这项工作首次展示了一种混合型诱导相干干涉仪，它结合了用于近可见光子的马赫-曾德型干涉仪和用于红外（IR）光子的迈克尔逊型干涉仪，基于双程泵浦自发参数下变频。这种配置通过检测近可见光子来实现红外光学测量，并提供通过识别不同来源的光子对来优化测量质量的方法。我们从理论上确定，诱导相干干涉可见度与沿相关空间模式的双光子之间的预示效率大致相同，并通过为红外光子设置公共参考空间模式来实验性地最大化可见度。演示了三维测试结构的时域和频域量子光学诱导相干断层扫描的应用。结果证明了基于所提出结构的实用未检测光子传感和成像技术的可行性。