Ultrafast all-optical switching by single photons

By T. Volz, A. Reinhard, M. Winger, Antonio Badolato, K. Hennessy, E. Hu, A. Imamoğlu. Nature Photonics, 2011

401 citations recorded by the source corpus.

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. Researchers report the first demonstration of an ultrafast all-optical switch in the single-photon regime. The device, which consists of an InAs/GaAs quantum dot in a photonic crystal defect cavity, exhibits a coherent coupling constant of 141 meV and a quality factor of 25,000. The overall switching time is around 50 ps.

Subfields: Atomic and Molecular Physics, and Optics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/0923d5d1a1dc326524f206a84cca16bc4bd77bab