Singlephoton detectors for optical quantum （Singlephoton光学量子探测器）.pdfVIP

review articleS | fOcus published online: 30 noVeMber 2009 |  doi: 10.1038/nphoton.2009.230 single-photon detectors for optical quantum information applications robert h. hadfield The past decade has seen a dramatic increase in interest in new single-photon detector technologies. A major cause of this trend has undoubtedly been the push towards optical quantum information applications such as quantum key distribution. These new applications place extreme demands on detector performance that go beyond the capabilities of established single-photon detectors. There has been considerable effort to improve conventional photon-counting detectors and to transform new device concepts into workable technologies for optical quantum information applications. This Review aims to highlight the significant recent progress made in improving single-photon detector technologies, and the impact that these developments will have on quantum optics and quantum information science. ne of Einstein’s key contributions to modern science was in advanced QI protocols10,11. We will outline accurate measurement to recognize that light is fundamentally composed of indi- strategies for characterizing single-photon detectors and discuss an Ovidual packets of energy, now referred to as photons1,2. The appropriate ‘figure of merit’ for quantifying detector performance. energy of a single photon in the visible or near-infrared range is around 10–19 J. A single-photon detector is an extremely sensitive Spectral range. A photon counter is only sensitive over a certain device capable of registering these quantum objects. Single-photon spectral range determined by its constituent materials. The operat- detectors now support and enable a host of applications at the fron- ing wavelength of interest depends