Homodyne detection in a photon counting application
Warren P. Grice · Journal of Modern Optics · 1996
A “which path” experiment is used as an illustrative example to show that homodyne detectors may be used in place of single-photon counting detectors in certain applications. In the case of interest, a single photon strikes a beam-splitter and the output beams are directed to a pair of homodyne detectors. Using Bayesian inference, the difference counts from the two detectors can be used to determine which path was taken by the photon. An error rate and effective efficiency are defined for the system, permitting direct comparison to conventional detection schemes. The calculations presented provide a framework for the analysis of homodyne detection in other photon counting applications.