Alloing, B.; Zinoni, C.; Zwiller, V.; Li, L.; Monat, C.; Gobet, M.; Buchs, G.; Fiore, A.; Pelucchi, E.; Kapon, E.

Zinoni, C.; Alloing, B.; Monat, C.; Zwiller, V.; Li, L.; Fiore, A.; Lunghi, L.; Gerardino, A.; Riedmatten, de, H.; Zbinden, H.; Gisin, N.

We experimentally observe a sizable and reversible spectral tuning of the resonances of a two-dimensional photonic crystal microcavity induced by the introduction of a subwavelength size glass tip. The comparison between experimental near-field data, collected with / 6 spatial resolution, and results of numerical calculations shows that the spectral shift induced by the tip is proportional to the local electric field intensity of the cavity mode. This observation proves that the electromagnetic local density of states in a microcavity can be directly measured by mapping the tip-induced spectral shift with a scanning near-field optical microscope.

Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers)Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication Citation for published version (APA):Zinoni, C., Alloing, B., Li, L., Marsili, F., Fiore, A., Lunghi, L., ... Gol'tsman, G. N. (2007). Single-photon experiments at telecommunication wavelengths using nanowire superconducting detectors. Applied Physics Letters, 91(3), 031106-1/3. [031106]. DOI: 10.1063/1.2752108 General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. The authors report fiber-coupled superconducting single-photon detectors with specifications that exceed those of avalanche photodiodes, operating at telecommunication wavelength, in sensitivity, temporal resolution, and repetition frequency. The improved performance is demonstrated by measuring the intensity correlation function g ͑2͒ ͑͒ of single-photon states at 1300 nm produced by single semiconductor quantum dots.

We demonstrate that the presence of charge around a semiconductor quantum dot (QD) strongly affects its optical properties and produces non-resonant coupling to the modes of a microcavity. We first show that, besides (multi)exciton lines, a QD generates a spectrally broad emission which efficiently couples to cavity modes. Its temporal dynamics shows that it is related to the Coulomb interaction between the QD (multi)excitons and carriers in the adjacent wetting layer. This mechanism can be suppressed by the application of an electric field, making the QD closer to an ideal twolevel system.