Photon-counting - measurement challenges

摘要

Low photon flux measurements are widely used in the fields of biology, nuclear physics, medical physics and astrophysics. This paper will highlight the key requirements and considerations needed for accurate, traceable measurement at these low light levels. A new driver for these techniques is the rapidly advancing field of optical quantum information processing1 which requires the development of single photon counting detectors, in addition to the wider use of optical technologies in the photon counting regime. The paper will present the results of the measurement of the quantum efficiency of a channel photomultiplier detector using an absolute radiometric technique based on correlated photons produced in non-linear crystals. Case studies will also be presented to illustrate this work.