Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Photon-number-discriminating detection using a quantum-dot, optically gated, field-effect transistor



Eric Gansen, Mary A. Rowe, M. Greene, Danna Rosenberg, Todd E. Harvey, Mark Su, Robert Hadfield, Sae Woo Nam, Richard Mirin


Detectors with the capability to directly measure the photon number of a pulse of light1-3 enable linear optics quantum computing4, affect the security of quantum communications5, and can be used to characterize6-8 and herald9 non-classical states of light. Here, we demonstrate the photon-number-resolving capabilities of a quantum dot, optically gated, field-effect transistor that uses quantum dots as optically addressable floating gates in a GaAs/Al0.2Ga0.8As delta-doped field-effect transistor. When the active area of the detector is illuminated, photo-generated carriers trapped by quantum dots screen the gate field, causing a persistent change in the channel current that is proportional to the number of confined carriers. Using weak laser pulses, we show that discrete numbers of trapped carriers produce well-resolved changes in the channel current. We demonstrate that for a mean photon number of 1.1,, decision regions can be defined such that the field-effect transistor determines the number of detected photons with a probability of accuracy greater than 83%.
Nature Photonics


photon-number resolution, quantum optics, single-photon detector


Gansen, E. , Rowe, M. , Greene, M. , Rosenberg, D. , Harvey, T. , Su, M. , Hadfield, R. , Nam, S. and Mirin, R. (2007), Photon-number-discriminating detection using a quantum-dot, optically gated, field-effect transistor, Nature Photonics, [online], (Accessed June 20, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created September 30, 2007, Updated October 12, 2021