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Observation of Single-Photon Switching

Yong-Fan Chen·Zen-Hsiang Tsai·Yu-Chen Liu·Ite A. Yu
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Abstract

We report an experimental demonstration of single-photon switching in laser-cooled $^{87}$Rb atoms. A resonant probe pulse with an energy per unit area of one photon per $λ^2/2π$ propagates through the optically thick atoms. Its energy transmittance is greater than 63% or loss is less than $e^{-1}$ due to the effect of electromagnetically induced transparency. In the presence of a switching pulse with an energy per unit area of 1.4 photons per $λ^2/2π$, the energy transmittance of the same probe pulse becomes less than 37% or $e^{-1}$. This substantial reduction of the probe transmittance caused by single switching photons has potential applications in single-photon-level nonlinear optics and the manipulation of quantum information.

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Yong-Fan Chen, Zen-Hsiang Tsai, Yu-Chen Liu, Ite A. Yu. 2005-01-31. Observation of Single-Photon Switching. https://arxiv.org/abs/physics/0501155

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