Ultrafast all-optical switching by single photons
Abstract
An outstanding goal in quantum optics is the realization of fast optical non-linearities at the single-photon level. Such non-linearities would allow for the realization of optical devices with new functionalities such as a single-photon switch/transistor or a controlled-phase gate, which could form the basis of future quantum optical technologies. While non-linear optics effects at the single-emitter level have been demonstrated in different systems, including atoms coupled to Fabry-Perot or toroidal micro-cavities, super-conducting qubits in strip-line resonators or quantum dots (QDs) in nano-cavities, none of these experiments so far has demonstrated single-photon switching on ultrafast timescales. Here, we demonstrate that in a strongly coupled QD-cavity system the presence of a single photon on one of the fundamental polariton transitions can turn on light scattering on a transition from the first to the second Jaynes-Cummings manifold with a switching time of 20 ps. As an additional device application, we use this non-linearity to implement a single-photon pulse-correlator. Our QD-cavity system could form the building-block of future high-bandwidth photonic networks operating in the quantum regime.
Cite
@article{arxiv.1111.2915,
title = {Ultrafast all-optical switching by single photons},
author = {Thomas Volz and Andreas Reinhard and Martin Winger and Antonio Badolato and Kevin J. Hennessy and Evelyn L. Hu and Atac Imamoglu},
journal= {arXiv preprint arXiv:1111.2915},
year = {2012}
}