多路复用探测系统以1024个探测仓精数光子：测至276个光子时不确定度小于1个
德国帕德博恩大学研究团队在《Optica》刊出的研究中报告，他们把超导纳米线单光子探测器与多路复用结合，建成1024个探测仓的系统，可精确计数从零到9000多个单个光子。论文题为Macroscopic photon counting beating the Poisson noise limit，数字对象标识为10.1364/optica.604389，第一作者为Timon Schapeler。
系统先把一个光脉冲分成128个在时间上错开的小脉冲，再分到8个探测器上，形成1024个小脉冲，原脉冲的光子数被分摊其间。团队结合逐仓的模型化标定，测得含多达276个光子的光脉冲时，测量不确定度小于单个光子。研究称，常规多路复用系统要达到同等精度约需37000个探测元件，而新系统只用1024个探测仓。测试中送入器件的激光脉冲平均光子数从每脉冲1个到15000个不等。
Schapeler表示，光子越多，精确计数越困难，新方法把光子计数扩展到更大的光子数，弥合了单光子测量与高灵敏光功率计之间的空白。团队成员Tim Bartley表示，大规模单光子测量是光子量子计算与单光子级成像的基石，新技术有助于了解光子量子计算机与单光子敏感相机如何扩展规模。团队计划下一步把该系统用于明亮的量子光态测量。
（来源：《Optica》）
A Multiplexed Detector With 1,024 Bins Counts Photons Precisely: Uncertainty Below One Photon at up to 276 Photons, in Optica
Researchers at Paderborn University in Germany described in Optica a detection system that combines superconducting nanowire single-photon detectors with multiplexing to create 1,024 detection bins, and can precisely count from zero to more than 9,000 individual photons. The paper, by Timon Schapeler and co-authors, is titled Macroscopic photon counting beating the Poisson noise limit, with digital object identifier 10.1364/optica.604389. The system splits one light pulse into 128 smaller pulses separated in time and then onto eight detectors, producing 1,024 smaller pulses that share the original number of photons between them. Together with model-informed characterization of each detection bin, the team measured light pulses containing up to 276 photons with an uncertainty smaller than a single photon. The researchers said a conventional multiplexed system would need about 37,000 detector elements to achieve the same precision, compared with their 1,024 detection bins. In testing, laser pulses sent to the device carried average photon numbers per pulse between one and 15,000. Schapeler said precisely counting photons becomes more challenging as their numbers increase, and that the approach extends photon counting to larger numbers of photons, bridging the gap between single-photon measurements and high-sensitivity optical power meters. Team member Tim Bartley said large-scale measurement of individual photons is a cornerstone of photonic quantum computing and single-photon-level imaging. The researchers plan to apply the system next to bright quantum states of light.
(Source: Optica)
来源：《Optica》
发布：GSM·美国（发布链接）
图片来源：图：实验室中的激光光学装置。Idaho National Laboratory，CC BY 2.0，经 Wikimedia Commons。 / Photo: Idaho National Laboratory, CC BY 2.0, via Wikimedia Commons.
GSM Global · 本篇英文版 English edition of this story
