Développement de lasers solides agiles ultra-stables pour la manipulation cohérente de systèmes atomiques

Développement de lasers solides agiles ultra-stables pour la manipulation cohérente de systèmes atomiques PDF Author: Vincent Crozatier
Publisher:
ISBN:
Category :
Languages : fr
Pages : 257

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Book Description
Dans cette thèse, nous utilisons les propriétés spectrales remarquables des cristaux dopés aux ions de terre rare pour effectuer des opérations de transformation de Fourier temps-fréquence. Nous présentons ainsi la première démonstration expérimentale de traitement cohérent de signaux radiofréquences (RF) sur une large bande. Notre système utilise une séquence d'excitation à base d'impulsions balayées en fréquence, dérivée du processus d'écho de photons. Par cet algorithme, le spectre du signal RF à analyser est projeté dans le temps. Expérimentalement, nous avons relevé d'excellentes performances dans un cristal de Er:Y2SiO5, utilisant une transition optique dans la fenêtre télécom. En effet, la bande passante instantanée atteint 1,5 GHz, avec 24 000 canaux spectraux d'analyse. La résolution peut quant à elle descendre à 50 kHz, et la dynamique d'analyse est de 32 dB. Ces résultats ont été obtenus grâce au développement spécifique d'une source laser, dont la fréquence peut être accordée sur plusieurs GHz en quelques μs. Une boucle d'asservissement permet d'offrir une excellente précision de ces balayages en fréquence. D'autres sources laser ont également été mises au point. L'une d'elle utilise des structures d'optique intégrée, et une autre est asservie sur une cavité optique de référence, pour affiner sa largeur d'émission sous le kHz. Par ailleurs, nous présentons une première étude d'échos de photons obtenus en milieu amplificateur dans un cristal de Er:Y2SiO5. Ainsi, le rendement énergétique du processus est augmenté. De nouveaux mécanismes déphasants hors équilibre sont également mis en avant lors de la génération de l'écho de photons.

Développement de lasers solides agiles ultra-stables pour la manipulation cohérente de systèmes atomiques

Développement de lasers solides agiles ultra-stables pour la manipulation cohérente de systèmes atomiques PDF Author: Vincent Crozatier
Publisher:
ISBN:
Category :
Languages : fr
Pages : 257

Get Book Here

Book Description
Dans cette thèse, nous utilisons les propriétés spectrales remarquables des cristaux dopés aux ions de terre rare pour effectuer des opérations de transformation de Fourier temps-fréquence. Nous présentons ainsi la première démonstration expérimentale de traitement cohérent de signaux radiofréquences (RF) sur une large bande. Notre système utilise une séquence d'excitation à base d'impulsions balayées en fréquence, dérivée du processus d'écho de photons. Par cet algorithme, le spectre du signal RF à analyser est projeté dans le temps. Expérimentalement, nous avons relevé d'excellentes performances dans un cristal de Er:Y2SiO5, utilisant une transition optique dans la fenêtre télécom. En effet, la bande passante instantanée atteint 1,5 GHz, avec 24 000 canaux spectraux d'analyse. La résolution peut quant à elle descendre à 50 kHz, et la dynamique d'analyse est de 32 dB. Ces résultats ont été obtenus grâce au développement spécifique d'une source laser, dont la fréquence peut être accordée sur plusieurs GHz en quelques μs. Une boucle d'asservissement permet d'offrir une excellente précision de ces balayages en fréquence. D'autres sources laser ont également été mises au point. L'une d'elle utilise des structures d'optique intégrée, et une autre est asservie sur une cavité optique de référence, pour affiner sa largeur d'émission sous le kHz. Par ailleurs, nous présentons une première étude d'échos de photons obtenus en milieu amplificateur dans un cristal de Er:Y2SiO5. Ainsi, le rendement énergétique du processus est augmenté. De nouveaux mécanismes déphasants hors équilibre sont également mis en avant lors de la génération de l'écho de photons.

Dictionary of the French and English Languages

Dictionary of the French and English Languages PDF Author: Gabriel Surenne
Publisher:
ISBN:
Category : Dictionaries (English-French).
Languages : en
Pages : 580

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Book Description


Introduction to Algorithms, third edition

Introduction to Algorithms, third edition PDF Author: Thomas H. Cormen
Publisher: MIT Press
ISBN: 0262258102
Category : Computers
Languages : en
Pages : 1313

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Book Description
The latest edition of the essential text and professional reference, with substantial new material on such topics as vEB trees, multithreaded algorithms, dynamic programming, and edge-based flow. Some books on algorithms are rigorous but incomplete; others cover masses of material but lack rigor. Introduction to Algorithms uniquely combines rigor and comprehensiveness. The book covers a broad range of algorithms in depth, yet makes their design and analysis accessible to all levels of readers. Each chapter is relatively self-contained and can be used as a unit of study. The algorithms are described in English and in a pseudocode designed to be readable by anyone who has done a little programming. The explanations have been kept elementary without sacrificing depth of coverage or mathematical rigor. The first edition became a widely used text in universities worldwide as well as the standard reference for professionals. The second edition featured new chapters on the role of algorithms, probabilistic analysis and randomized algorithms, and linear programming. The third edition has been revised and updated throughout. It includes two completely new chapters, on van Emde Boas trees and multithreaded algorithms, substantial additions to the chapter on recurrence (now called “Divide-and-Conquer”), and an appendix on matrices. It features improved treatment of dynamic programming and greedy algorithms and a new notion of edge-based flow in the material on flow networks. Many exercises and problems have been added for this edition. The international paperback edition is no longer available; the hardcover is available worldwide.

Product Life-Cycle Management

Product Life-Cycle Management PDF Author: Max Giordano
Publisher: John Wiley & Sons
ISBN: 1118587529
Category : Business & Economics
Languages : en
Pages : 389

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Book Description
This book gives a comprehensive view of the most recent major international research in the field of tolerancing, and is an excellent resource for anyone interested in Computer Aided Tolerating. It is organized into 4 parts. Part 1 focuses on the more general problems of tolerance analysis and synthesis, for tolerancing in mechanical design and manufacturing processes. Part 2 specifically highlights the simulation of assembly with defects, and the influence of tolerances on the quality of the assembly. Part 3 deals with measurement aspects, and quality control throughout the life cycle. Different measurement technologies and methods for estimating uncertainty are considered. In Part 4, different aspects of tolerancing and their interactions are explored, from the definition of functional requirement to measurement processes in a PLM approach.

Graphite Intercalation Compounds II

Graphite Intercalation Compounds II PDF Author: Hartmut Zabel
Publisher: Springer Science & Business Media
ISBN: 3642844790
Category : Science
Languages : en
Pages : 442

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Book Description
The research on graphite intercalation compounds often acts as a forerunner for research in other sciences. For instance, the concept of staging, which is fundamental to graphite intercalation compounds, is also relevant to surface science in connection with adsorbates on metal surfaces and to high-temperature superconducting oxide layer materials. Phonon-folding and mode-splitting effects are not only basic to graphite intercalation compounds but also to polytypical systems such as supercon ductors, superlattices, and metal and semiconductor superlattices. Charge transfer effects playa tremendously important role in many areas, and they can be most easily and fundamentally studied with intercalated graphite. This list could be augmented with many more examples. The important message, however, is that graphite inter calation compounds represent a class of materials that not only can be used for testing a variety of condensed-matter concepts, but also stimulates new ideas and approaches. This volume is the second of a two-volume set. The first volume addressed the structural and dynamical aspects of graphite intercalation compounds, together with the chemistry and intercalation of new compounds. This second volume provides an up-to-date status report from expert researchers on the transport, magnetic, elec tronic and optical properties ofthis unique class of materials. The band-structure cal culations of the various donor and acceptor compounds are discussed in depth, and detailed reviews are provided ofthe experimental verification ofthe electronic struc ture in terms of their photoemission spectra and optical properties.

Diffusion in Materials - DIMAT 2011

Diffusion in Materials - DIMAT 2011 PDF Author: I. Bezverkhyy
Publisher:
ISBN: 9783037853979
Category : Diffusion
Languages : en
Pages : 0

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Book Description
The International Conference on Diffusion in Materials (DIMAT) is the benchmark conference series for diffusion in solids. DIMAT 2011 was organized by the University of Bourgogne in association with CNRS, Dijon (France). The conference showcased new results concerning theoretical tools as well as applied research approaches. Diffusion processes affect all types of materials: nanomaterials, materials for energy, metallurgy, glasses and ceramics, but each requires its own numerical tools.Volume is indexed by Thomson Reuters CPCI-S (WoS). This volume comprises most of the contributions presented at DIMAT 2011: 4 plenary lectures delivered by famous high-level scientists plus 88 contributions in the form of keynote lectures, talks and posters.

Historical Dictionary of Iran

Historical Dictionary of Iran PDF Author: John Henry Lorentz
Publisher: Historical Dictionaries of Asia, Oceania, and the Middle East
ISBN:
Category : History
Languages : en
Pages : 570

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Book Description
Provides an overview of specific events, movements, people, political and social groups, places, trends, and chronology. Allows for considerable exploration of a number of historical and contemporary topics and issues. The modern period, defined as 1800-present, is covered extensively.

Interactive Multimodal Information Management

Interactive Multimodal Information Management PDF Author: Hervé Bourlard
Publisher: EPFL Press
ISBN: 2940222711
Category : Reference
Languages : en
Pages : 369

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Book Description
In the past twenty years, computers and networks have gained a prominent role in supporting human communications. This book presents recent research in multimodal information processing, which demonstrates that computers can achieve more than what telephone calls or videoconferencing can do. The book offers a snapshot of current capabilities for the analysis of human communications in several modalities – audio, speech, language, images, video, and documents – and for accessing this information interactively. The book has a clear application goal, which is the capture, automatic analysis, storage, and retrieval of multimodal signals from human interaction in meetings. This goal provides a controlled experimental framework and helps generating shared data, which is required for methods based on machine learning. This goal has shaped the vision of the contributors to the book and of many other researchers cited in it. It has also received significant long-term support through a series of projects, including the Swiss National Center of Competence in Research (NCCR) in Interactive Multimodal Information Management (IM2), to which the contributors to the book have been connected.

Connected Objects in Health

Connected Objects in Health PDF Author: Laure Beyala
Publisher: Elsevier
ISBN: 0081023723
Category : Medical
Languages : en
Pages : 186

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Book Description
Connected objects today present a range of opportunities in medicine. We live in a new digital era where the monitoring and analysis of one's own health information no longer belongs solely to the realm of science fiction. The success of these new devices resides in their usage, which integrates seamlessly into the daily life of the user in order to continually collect the maximum amount of data. These medical connected devices therefore constitute a new hope in transforming user experience as well as the care pathway. They offer a better level of support and a better quality of life for those suffering from chronic illnesses or mental, sensorial or physical disabilities. However, these solutions also pose systematic problems, especially regarding the risks linked to their usage. This book presents a cartography which clearly details all the potential risk scenarios linked to the usage of connected devices as well as the actions which should be undertaken to promote balanced governance and guarantee the development of high-quality medical devices. - Aims to help the reader understand the difference between a connected object and a medical connected device - Identifies and evaluates all the potential risks and perspectives associated with the use of connected medical devices - Shows how to make a comprehensive risk analysis with standards like ISO 31000 and 14971

Theory Of Superconductivity

Theory Of Superconductivity PDF Author: J. Robert Schrieffer
Publisher: CRC Press
ISBN: 0429964250
Category : Science
Languages : en
Pages : 352

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Book Description
Theory of Superconductivity is primarily intended to serve as a background for reading the literature in which detailed applications of the microscopic theory of superconductivity are made to specific problems.