Ultrafast infrared superconducting single-photon detectors

爱因斯坦对现代科学的重要贡献之一是认识到光基本上是由称为光子的离散能量包组成的。单光子探测器是一种非常灵敏的设备，能够对这些单个量子物体进行计数-在低光强下，光子的到达可以像锡屋顶上的第一个雨滴图案一样清晰地区分开来。较低能量（红外）光子被典型的传输介质（大气、光纤甚至活体组织）吸收和散射的强度低于可见光波长的光子。因此，红外单光子探测器是一种关键的技术，可用于许多科学应用，从最终的安全通信（量子密码学）到新的医学成像方法。当尝试用传统的基于光子计数器的探测器进行红外单光子计数时，会遇到严重的问题。这种技术差距是一个重大障碍，研究人员在一系列领域。该建议是基于一种新型的单光子探测器，能够记录低能量光子前所未有的定时分辨率。该探测器是微型化-纳米技术领域最新进展的产物。它是由一个超窄（“纳米”）线，冷却到低温，使其进入超导状态。商业封闭循环冷却技术现在使这种未来探测器在实际应用中变得可行。该提案旨在在英国建立一个世界级的研究计划，以改进和利用这一极具前景的新技术。该方案将在爱丁堡赫瑞瓦特大学进行，该大学是欧洲领先的光子学中心之一。一开始的关键目标是为这些探测器建立一个光学测试平台，进一步提高它们的性能，并将它们用于开创性的新单光子计数应用。这一建议应在新的科学和技术应用方面产生强大的影响。

One of Einstein's key contributions to modern science was to recognize that light is fundamentally composed of discrete packets of energy known as photons. A single photon detector is an extremely sensitive device capable of counting these individual quantum objects - at low light intensities the arrival of photons can be distinguished as clearly as the first patter of raindrops on a tin roof. Lower energy (infrared) photons are less strongly adsorbed and scattered by typical transmission media (the atmosphere, optical fibre or even living tissue) than photons at visible wavelengths. Hence infrared single-photon detectors are a crucial enabling technology for a host of scientific applications, ranging from the ultimate in secure communications (quantum cryptography), to new methods of medical imaging. Serious problems are encountered when attempting infrared single-photon counting with conventional semiconductor-based detectors. This technological gap represents a significant obstacle for researchers across a range of fields. This proposal is based upon a new type of single photon-detector capable of registering low energy photons with unprecedented timing resolution. This detector is a product of recent advances in the art of miniaturization -Nanotechnology. It is comprised of an ultra-narrow ('nanoscale') wire, cooled to low temperature such that it enters the superconducting state. Commercial closed-cycle cooling technology now makes this futuristic detector viable for practical applications. This proposal aims to set up a world class research programme in the UK based on improving and exploiting this highly promising new technology. This programme will be carried out at Heriot-Watt University, Edinburgh, which is one of the leading photonics centres in Europe. Key goals at the outset are to set up an optical test bed for these detectors, to further improve their performance, and to employ them in groundbreaking new single-photon counting applications. This proposal should have a powerful impact in terms of new science and technological applications.