Improving the performance of bright quantum dot single photon sources using amplitude modulation

Single epitaxially-grown semiconductor quantum dots have great potential as single photon sources for photonic quantum technologies, though in practice devices often exhibit non-ideal behavior. Here, we demonstrate that amplitude modulation can improve the performance of quantum-dot-based sources. Starting with a bright source consisting of a single quantum dot in a fiber-coupled microdisk cavity, we use synchronized amplitude modulation to temporally filter the emitted light. We observe that the single photon purity, temporal overlap between successive emission events, and indistinguishability can be greatly improved with this technique. As this method can be applied to any triggered single photon source, independent of geometry and after device fabrication, it is a flexible approach to improve the performance of solid-state systems, which often suffer from excess dephasing and multi-photon background emission

Properties of a single photon generated by a solid-state emitter: effects of pure dephasing

We investigate the properties of a single photon generated by a solid-state emitter subject to strong pure dephasing. We employ a model in which all the elements of the system, including the propagating fields, are treated quantum mechanically. We analytically derive the density matrix of the emitted photon, which contains full information about the photon, such as its pulse profile, power spectrum, and purity. We visualize these analytical results using realistic parameters and reveal the conditions for maximizing the purity of generated photons.Comment: 25pages(one column), 10 figure

Photons indiscernables : qui se ressemble, s'assemble

Les boîtes quantiques semi-conductrices sont des candidats prometteurs pour la génération d'états quantiques de la lumière, tels que des photons uniques. En isolant ces nano-émetteurs dans des microcavités optiques, ces émetteurs uniques peuvent produire des photons identiques : l'exaltation du taux d'émission spontanée permet de contourner les effets de perte de cohérence de l'émetteur, qui marquent aléatoirement les photons émis. L'indiscernabilité entre photons est sondée via des expériences d'interférence à deux photons. La visibilité du processus d'interférence indique des taux d'indiscernabilité supérieurs à 70% entre photons émis par une boîte isolée en cavité micropilier ou à cristal photonique

Generation of non-classical light by single quantum dots

The emission statistics of single semiconductor quantum dots is investigated in view of generating quantum states of light. Correlation experiments show that the emission of a quantum dot can be regulated so as to produce only one photon at a time as well as correlated photon pairs. This observation opens the way to the use of semiconductor quantum dots as triggered sources of single photons, which could find applications in quantum cryptography. We then discuss the potentiality of quantum dots for the production of mutually coherent single photons as well as entangled photons that could be used in quantum information processing schemes. © 2002 Elsevier Science B.V. All rights reserved