Matériaux à bandes interdites photoniques PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Matériaux à bandes interdites photoniques PDF full book. Access full book title Matériaux à bandes interdites photoniques by D. Cassagne. Download full books in PDF and EPUB format.
Author: D. Cassagne
Publisher:
ISBN: 9782868833877
Category : Dielectric devices
Languages : fr
Pages : 91
Get Book Here
Book Description
LES MATERIAUX A BANDES INTERDITES PHOTONIQUES SONT DES STRUCTURES DIELECTRIQUES PERIODIQUES QUI CONTROLENT LA PROPAGATION DES ONDES ELECTROMAGNETIQUES. DANS CE MEMOIRE, NOUS DECRIVONS LA METHODE DES ONDES PLANES QUI PERMET DE CALCULER LES STRUCTURES DE BANDES DES CRISTAUX PHOTONIQUES. PAR UNE ANALYSE DE LA SYMETRIE ET UNE APPROCHE PERTURBATIVE, NOUS PRECISONS LES CONDITIONS D'EXISTENCE DES BANDES INTERDITES DE BASSE ENERGIE. NOUS PROPOSONS DE NOUVELLES STRUCTURES BIDIMENSIONNELLES APPELEES GRAPHITE ET NITRURE DE BORE. GRACE A UNE METHODE DE MATRICES DE TRANSFERT, NOUS CALCULONS LA TRANSMISSION DE LA STRUCTURE GRAPHITE ET NOUS METTONS EN EVIDENCE LE ROLE FONDAMENTAL DU COUPLAGE AVEC LES MODES EXTERIEURS. NOUS ETUDIONS L'APPARITION DE MODES PERMIS DANS LA BANDE INTERDITE GRACE A L'INTRODUCTION DE DEFAUTS DANS LA PERIODICITE. ENFIN, NOUS DISCUTONS LES PROPRIETES DES OPALES CONSTITUEES DE MICRO-BILLES DE SILICE AUTO-ORGANISEES QUI SONT TRES PROMETTEUSES POUR LA FABRICATION DE CRISTAUX PHOTONIQUES TRIDIMENSIONNELS.
Author: D. Cassagne
Publisher:
ISBN: 9782868833877
Category : Dielectric devices
Languages : fr
Pages : 91
Get Book Here
Book Description
LES MATERIAUX A BANDES INTERDITES PHOTONIQUES SONT DES STRUCTURES DIELECTRIQUES PERIODIQUES QUI CONTROLENT LA PROPAGATION DES ONDES ELECTROMAGNETIQUES. DANS CE MEMOIRE, NOUS DECRIVONS LA METHODE DES ONDES PLANES QUI PERMET DE CALCULER LES STRUCTURES DE BANDES DES CRISTAUX PHOTONIQUES. PAR UNE ANALYSE DE LA SYMETRIE ET UNE APPROCHE PERTURBATIVE, NOUS PRECISONS LES CONDITIONS D'EXISTENCE DES BANDES INTERDITES DE BASSE ENERGIE. NOUS PROPOSONS DE NOUVELLES STRUCTURES BIDIMENSIONNELLES APPELEES GRAPHITE ET NITRURE DE BORE. GRACE A UNE METHODE DE MATRICES DE TRANSFERT, NOUS CALCULONS LA TRANSMISSION DE LA STRUCTURE GRAPHITE ET NOUS METTONS EN EVIDENCE LE ROLE FONDAMENTAL DU COUPLAGE AVEC LES MODES EXTERIEURS. NOUS ETUDIONS L'APPARITION DE MODES PERMIS DANS LA BANDE INTERDITE GRACE A L'INTRODUCTION DE DEFAUTS DANS LA PERIODICITE. ENFIN, NOUS DISCUTONS LES PROPRIETES DES OPALES CONSTITUEES DE MICRO-BILLES DE SILICE AUTO-ORGANISEES QUI SONT TRES PROMETTEUSES POUR LA FABRICATION DE CRISTAUX PHOTONIQUES TRIDIMENSIONNELS.
Author: Rodrigue Roland Mafouana
Publisher:
ISBN:
Category :
Languages : fr
Pages : 204
Get Book Here
Book Description
Ce travail porte sur la réalisation de matériaux à bandes interdites photoniques (BIP) dans le domaine du visible à base d’opales artificielles.La première phase que nous abordé a été l’élaboration des opales et plus particulièrement la préparation de suspensions colloïdales par la méthode de Stöber. Pour obtenir une auto-organisation des particules de silice de bonne qualité nous avons travaillé à l’affinement de la distribution en taille des particules de silice. Nous avons montré que pour notre dispositif opératoire il est nécessaire que les réactifs soient purifiés et thermostatés à 40°C puis que la réaction soit menée sous agitation moyenne (500 tr.min-1). Les suspensions colloïdales sont stabilisées par extraction des particules et remises en suspension dans l’eau puis par chauffage à 120°C/30min. La structure interne des particules de silice montre une nanoporosité. Les opales ont été élaborées par électrosédimentation et consolidées à 950°C. Les propriétés optiques optimales, réflectivité maximale, ont été obtenues pour un recuit de 4 heures.La deuxième partie de ce travail a porté sur l’utilisation d’opales de silice comme préforme pour infiltrer le réseau poreux et construire des opales inverses plus prometteuses en terme de matériau photonique. Nous avons infiltré les opales précédentes par des matériaux à fort indice (TiO2, ZrO2, Métaux magnétiques, Or) soit par imprégnations successives soit par électro-cristallisation. C’est la deuxième méthode qui a donné des résultats les plus satisfaisants.La troisième partie de ce travail concerne la mise au point d’une méthode l’élaboration de cristaux photoniques par dépôt de nappes successives de particules. Des monocouches de bonnes qualités ont été obtenues avec des suspensions colloïdales contenant entre 5,5 et 9 mol.L-1 de silice sous la forme de particules d’environ 300nm et une vitesse d’extraction de 11,5 mm.min-1. Ces méta-cristaux bidimensionnels de symétrie hexagonale montrent une bonne efficacité de diffraction. Par contre la qualité des couches suivantes se dégrade rapidement.La stabilité mécanique et la grande qualité de la structuration des monocouches de billes de silice sur ces substrats a rendu possible leur utilisation pour la nanostructuration 2D de plots métalliques et la réalisation d’un laser à réaction distribuée.
Author: Ahmed Belasri
Publisher: Springer Nature
ISBN: 9811554447
Category : Technology & Engineering
Languages : en
Pages : 659
Get Book Here
Book Description
This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.
Author: John Wilfred Orton
Publisher:
ISBN: 0199695822
Category : Science
Languages : en
Pages : 529
Get Book Here
Book Description
The book is a history of Molecular Beam Epitaxy (MBE) as applied to the growth of semiconductor thin films (note that it does not cover the subject of metal thin films). It begins by examining the origins of MBE, first of all looking at the nature of molecular beams and considering their application to fundamental physics, to the development of nuclear magnetic resonance and to the invention of the microwave MASER. It shows how molecular beams of silane (SiH4) were used to study the nucleation of silicon films on a silicon substrate and how such studies were extended to compound semiconductors such as GaAs. From such surface studies in ultra-high vacuum the technique developed into a method of growing high quality single crystal films of a wide range of semiconductors. Comparing this with earlier evaporation methods of deposition and with other epitaxial deposition methods such as liquid phase and vapour phase epitaxy (LPE and VPE). The text describes the development of MBE machines from the early 'home-made' variety to that of commercial equipment and show how MBE was gradually refined to produce high quality films with atomic dimensions. This was much aided by the use of various in-situ surface analysis techniques, such as reflection high energy electron diffraction (RHEED) and mass spectrometry, a feature unique to MBE. It looks at various modified versions of the basic MBE process, then proceed to describe their application to the growth of so-called 'low-dimensional structures' (LDS) based on ultra-thin heterostructure films with thickness of order a few molecular monolayers. Further chapters cover the growth of a wide range of different compounds and describe their application to fundamental physics and to the fabrication of electronic and opto-electronic devices. The authors study the historical development of all these aspects and emphasise both the (often unexpected) manner of their discovery and development and the unique features which MBE brings to the growth of extremely complex structures with monolayer accuracy.
Author: Stefano Boccaletti
Publisher: A I P Press
ISBN:
Category : Mathematics
Languages : en
Pages : 384
Get Book Here
Book Description
The 8th Experimental Chaos Conference again demonstrated the broad spectrum of areas where nonlinear dynamics plays an important role, such as circuits, hydrodynamics, optics, chemistry, fracture dynamics, neuroscience, and cognitive science. Additional contributions outline the trends for development and application of concepts and techniques of nonlinear dynamics.
Author: Sébastien Forget
Publisher: Springer
ISBN: 3642367054
Category : Science
Languages : en
Pages : 179
Get Book Here
Book Description
Organic lasers are broadly tunable coherent sources, potentially compact, convenient and manufactured at low-costs. Appeared in the mid 60’s as solid-state alternatives for liquid dye lasers, they recently gained a new dimension after the demonstration of organic semiconductor lasers in the 90's. More recently, new perspectives appeared at the nanoscale, with organic polariton and surface plasmon lasers. After a brief reminder to laser physics, a first chapter exposes what makes organic solid-state organic lasers specific. The laser architectures used in organic lasers are then reviewed, with a state-of-the-art review of the performances of devices with regard to output power, threshold, lifetime, beam quality etc. A survey of the recent trends in the field is given, highlighting the latest developments with a special focus on the challenges remaining for achieving direct electrical pumping of organic semiconductor lasers. A last chapter covers the applications of organic solid-state lasers.
Author: Agnes Buka
Publisher: World Scientific
ISBN: 1848167997
Category : Science
Languages : en
Pages : 299
Get Book Here
Book Description
The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.
Author: Jacques Lafontaine
Publisher: Springer
ISBN: 3319207350
Category : Mathematics
Languages : en
Pages : 408
Get Book Here
Book Description
This book is an introduction to differential manifolds. It gives solid preliminaries for more advanced topics: Riemannian manifolds, differential topology, Lie theory. It presupposes little background: the reader is only expected to master basic differential calculus, and a little point-set topology. The book covers the main topics of differential geometry: manifolds, tangent space, vector fields, differential forms, Lie groups, and a few more sophisticated topics such as de Rham cohomology, degree theory and the Gauss-Bonnet theorem for surfaces. Its ambition is to give solid foundations. In particular, the introduction of “abstract” notions such as manifolds or differential forms is motivated via questions and examples from mathematics or theoretical physics. More than 150 exercises, some of them easy and classical, some others more sophisticated, will help the beginner as well as the more expert reader. Solutions are provided for most of them. The book should be of interest to various readers: undergraduate and graduate students for a first contact to differential manifolds, mathematicians from other fields and physicists who wish to acquire some feeling about this beautiful theory. The original French text Introduction aux variétés différentielles has been a best-seller in its category in France for many years. Jacques Lafontaine was successively assistant Professor at Paris Diderot University and Professor at the University of Montpellier, where he is presently emeritus. His main research interests are Riemannian and pseudo-Riemannian geometry, including some aspects of mathematical relativity. Besides his personal research articles, he was involved in several textbooks and research monographs.
Author: P. M. Banks
Publisher: Elsevier
ISBN: 1483260666
Category : Science
Languages : en
Pages : 445
Get Book Here
Book Description
Aeronomy, Part A is an attempt to make a comprehensive exposition of the processes in aeronomy, the study of composition, movement, and thermal balance of the upper regions of the planetary atmosphere. The text covers topics such as atmospheric regions and atmospheric density, the temperature and molecular mass of the atmosphere; the permanent constituents and the molecular and isotonic composition of the homosphere; and the transition from the homosphere to the heterosphere. Also covered are topics such as the temperature gradient and energies in the thermosphere, conditions at 200km and above 250km, solar radiation and ionization, and aeronomic reactions. The book is recommended for scientists, especially natural physicists, who would like to know more about the field of aeronomy and its advances.
Author: Jean-Marie Basset
Publisher: John Wiley & Sons
ISBN: 3527627103
Category : Science
Languages : en
Pages : 725
Get Book Here
Book Description
Covering everything from the basics to recent applications, this monograph represents an advanced overview of the field. Edited by internationally acclaimed experts respected throughout the community, the book is clearly divided into sections on fundamental and applied surface organometallic chemistry. Backed by numerous examples from the recent literature, this is a key reference for all chemists.
