发表机构
Department of Physics, City University of Hong Kong（香港城市大学物理系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对量子望远镜术，利用实际反聚束光子源产生参考场，在考虑探测系统不完美性和有限带宽下优化信噪比，发现其可超越弱相干态方案，为实验提供指导。
AI 中文摘要
Grottesman等人提出的量子望远镜术利用空间纠缠单光子态来改进HBT恒星干涉测量，在无基线限制的情况下，其分辨率有望超越迈克尔逊干涉测量。然而，有限的光源带宽、非单位效率、探测器响应时间以及天体光带宽都会影响其有效性。在本工作中，我们考虑由分束一个来自共振荧光的实际反聚束光子源（一种常见的单光子态产生方法）所产生的空间纠缠单光子态，并在包含探测系统不完美性和天体光有限带宽的情况下评估量子望远镜术中的信号水平。在此，给定入射光，我们优化反聚束光子源和探测器系统的参数以获得最佳信噪比（SNR），该信噪比在理想情况下可与迈克尔逊方法匹配，但在实际情况下总是更小。或者，来自重度衰减激光器的弱相干态可以替代纠缠单光子态，但会遭受低信号水平，类似于HBT方法。我们发现，在弱入射场极限下，使用实际反聚束源产生参考场的信噪比仍可超越相干态方案的信噪比。反聚束源和探测系统的优化参数将为未来的实验努力提供指导。
英文摘要
Quantum telescopy, proposed by Grottesman et al., uses spatially entangled single-photon states to modify HBT stellar interferometry, potentially surpassing Michelson interferometry in resolution without baseline limits. However, finite source bandwidth, non-unit efficiency, detector response times, and celestial light bandwidth all affect its effectiveness. In this work, we consider a spatially entangled singe-photon state generated by beam-splitting a practical anti-bunched photon source from resonance fluorescence, which is a common method of generating single-photon states, and evaluate the signal level in quantum telescopy with inclusion of imperfection of detection system and finite bandwidth of celestial light. Here, given the incoming light, we optimize the parameters of the anti-bunched photon source and the detector system for the best signal-to-noise ratio (SNR), which can match that of the Michelson method in the ideal case but is always smaller in the realistic case. Alternatively, weak coherent states from heavily attenuated lasers can replace the entangled single-photon state but suffer low signal level, similar to HBT method. We find that the SNR with a realistic anti-bunched source for producing the reference fields can still beat the SNR of the coherent state scheme in the weak incoming field limit. The optimized parameters for the anti-bunched source and detection system will be a guide for future experimental endeavor.
Comments10 pages, 6 figures
