Abstract
As single-photon sources become more mature and are used more often in quantum information, communications, and measurement applications, their characterization becomes more important. Single-photon-like light is often characterized by its brightness, as well as two quantum properties: the suppression of multiphoton content and the photon indistinguishability. While it is desirable to obtain these quantities from a single measurement, currently two or more measurements are required. Here, we show that using two-photon () number-resolving detectors, one can completely characterize single-photon-like states in a single measurement, where previously two or more measurements were necessary. We simultaneously determine the brightness, the suppression of multiphoton states, the indistinguishability, and the statistical distribution of Fock states to third order for a quantum light source. We find number-resolving detectors provide no additional advantage in the single-photon characterization. The new method extracts more information per experimental trial than a conventional measurement for all input states and is particularly more efficient for statistical mixtures of photon states. Thus, using this , number-resolving detector scheme will provide advantages in a variety of quantum optics measurements and systems.
- Received 25 January 2017
DOI:https://doi.org/10.1103/PhysRevX.7.041036
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society
Physics Subject Headings (PhySH)
Popular Summary
Light can behave as if it is made from discrete particles known as photons. Most light sources are made from vast numbers of photons. But some emerging technologies based on quantum information science and quantum optics require single photons. Moreover, these single photons should be bright, indistinguishable, and free of multiphoton content. Typically, two (or more) measurements are needed to verify these requirements. We demonstrate a new way to fully characterize single-photon states in a single measurement for the first time. The technique is based on the concept of photon-number-resolving detectors.
Our demonstration uses the bright single-photon light from a semiconductor quantum dot. Notably, we replace the typical single-photon detectors and instead emulate photon-number-resolving detectors that are capable of differentiating between one and two photons. Rarely in quantum optics does such a substitution fundamentally change the measurement by not only providing better accuracy but also enabling a simultaneous measurement of two different physical quantities.
We have shown that number-resolving detectors can advance the characterization of light and should also improve a diverse set of quantum optics experiments.