Ultrafast all-optical switching by single photons

Volz, T., Reinhard, A., Winger, M., Badolato, A. , Hennessy, K. J., Hu, E. L. and Imamoğlu, A. (2012) Ultrafast all-optical switching by single photons. Nature Photonics, 6(9), pp. 605-609. (doi: 10.1038/nphoton.2012.181)

Abstract

An as yet outstanding goal in quantum optics is the realization of fast optical nonlinearities at the single-photon level. This would allow for the implementation of optical devices with new functionalities such as single-photon switches/transistors1,2 or controlled-phase gates3. Although nonlinear optics effects at the single-emitter level have been demonstrated in a number of systems4,5,6,7,8,9,10,11,12,13, none of these experiments showed single-photon switching on ultrafast timescales. Here, we perform pulsed two-colour spectroscopy and demonstrate that, in a strongly coupled quantum dot–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. The overall switching time of this single-photon all-optical switch14 is ∼50 ps. In addition, we use the single-photon nonlinearity to implement a pulse correlator. Our quantum dot–cavity system could form the building block of future high-bandwidth photonic networks operating in the quantum regime15,16,17,18.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Badolato, Professor Antonio
• Authors: Volz, T., Reinhard, A., Winger, M., Badolato, A., Hennessy, K. J., Hu, E. L., and Imamoğlu, A.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Nature Photonics
• Publisher: Nature Publishing Group
• ISSN: 1749-4885
• ISSN (Online): 1749-4893
• Published Online: 12 August 2012