Physics

Optical Transistor Flips On with One Photon

Charles S. Adams

Published Jul 28, 2014• 2 citations

Abstract

An all-optical transistor is a device in which a gate light pulse switches the transmission of a target light pulse with a gain above unity.The gain quantifies the change of the transmitted target photon number per incoming gate photon.We study the quantum limit of one incoming gate photon and observe a gain of 20.The gate pulse is stored as a Rydberg excitation in an ultracold gas.The transmission of the subsequent target pulse is suppressed by Rydberg blockade, which is enhanced by a Förster resonance.The detected target photons reveal in a single shot with a fidelity above 0.86 whether a Rydberg excitation was created during the gate pulse.The gain offers the possibility to distribute the transistor output to the inputs of many transistors, thus making complex computational tasks possible.

DOI: 10.1103/physics.7.80

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