Nanostructures photoniques ultimes pour l'information quantique

The current demand of digital communications (mobile phones, email, e-commerce ...) requires the development of systems which can guarantee full confidentiality. The use of quantum mechanics laws as a way of encryption is considered as an efficient way to meet confidentiality requirements. While physicists have begun to think about this type of encryption since the 1970s, the practical devices with large scale manufacturability are not yet available. Among devices to be developed, light sources capable of generating photons per unit are the most promising. One of the main difficulties encountered in their development is the need to achieve a collection efficiency of the emitted light close to unity. The solution usually proposed is to control their electromagnetic environment using optical resonators miniaturized at the wavelength scale. Thus, we can benefit from quantum electrodynamics effects, as the Purcell effect, in order to improve for example the dynamics and/or the directivity of the emitted photons. The practical realization of photon sources has been made possible by advances in nanotechnology. The use of semiconductor technology is the promising way chosen in this work, in view of developing miniaturized and easily integrated components to lay foundations for a new generation of ultimate-size optical resonators. In this thesis, we propose to develop a single photon source using InAs/GaAs quantum dots -as single emitters - inserted in a GaAs membrane. The quantum dots are coupled to an optical resonator consisting in a photonic crystal cavity formed in the GaAs membrane. Use of the photonic crystal approach allows for the generation of a single-resonant-optical mode so called non degenerated slow Bloch mode, operating above the light line, hence providing efficient communication with free space. We employ various numerical methods for designing and simulating the electromagnetic behaviours of the devices. Thus, we perform a fine engineering of the optical modes in order to:(1) optimize the Purcell factor in a photonic heterostructure (where photonics wells are equivalent to electronic quantum wells). We show that the positioning of a Bragg mirror above the cavity results in a two-fold increase of the collection efficiency of photons, as well as of their emission dynamics;(2) control the directivity of the emission diagram, thus improving the efficiency of extraction/collection of photons. A detailed engineering study of the radiation pattern is presented in12order to predict the features of the emission diagram. We show in particular that the presence of the Bragg mirror may alter the directivity of the emission if its location is not properly optimized. Technological developments meant to result in high quality photonic resonators are described. A wavelength of 900nm of the emission is chosen for an optimal matching to the detector characteristics, which requires a period of the photonic crystal in the range of a few hundreds of nm. The tools and technological parameters of manufacturing (eg, calibration of the thickness of hard mask and exposure parameters of the resist by electron beam lithography) are detailed.

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Source https://theses.hal.science/tel-00676648
Author Nedel, Patrick
Maintainer CCSD
Last Updated May 25, 2026, 17:11 (UTC)
Created May 25, 2026, 17:11 (UTC)
Identifier NNT: 2010ECDL0011
Language fr
Rights https://about.hal.science/hal-authorisation-v1/
contributor INL - Nanophotonique (INL - Photonique) ; Institut des Nanotechnologies de Lyon (INL) ; École Centrale de Lyon (ECL) ; Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon) ; Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL) ; Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon) ; Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
creator Nedel, Patrick
date 2010-06-25T00:00:00
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metadata_modified 2025-02-20T00:00:00
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