Characterization of a Femtosecond Laser and Its Application to the Study of Breakdown in Dielectric Thin Films PDF Download

Author: Jayesh C. Jaspara
Publisher:
ISBN:
Category : Breakdown (Electricity)
Languages : en
Pages : 284

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Author:
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ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 776

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Author: Nikita Shcheblanov
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
With the appearance of new ultra-short laser systems, extremely high laser intensities became accessible thus allowing laser treatment of practically all materials. As a result, extremely precise processing techniques are under development considerably extending the number of the corresponding industrial and medical applications. Further progress in this field requires a better understanding of fundamental processes involved in the laser interactions. In addition, the success of several national and international involving the development and use of high power laser systems depends on the capacity of careful definition of damage threshold of their optical components. These points illustrate the importance of a detailed numerical modeling of laser interactions with dielectric materials. Under laser irradiation, seed electrons appear in the conduction band of dielectric materials due to photo-ionization process. Colliding with a third-body, these electrons are further heated in laser field. When the threshold electron energy is reached, electron-impact ionization begins. At the same time, the considered laser pulses are so short that electron sub-system has no time to reach an equilibrium state. The resulting optical properties are affected and the definition of the damage criterion should be revised. The proposed approach accounts for the non-equilibrium and provides a detailed description of all the involved processes. In particular, we consider the photo- and impact-ionization processes, as well as electron-electron, electron-phonon and electron-ion collisions. The electron energy distribution and heating of electronic and phonon subsystems is discussed. The role of laser parameters (wavelength, pulse duration, fluence) and material properties (energy gap, band structure) is investigated. The thermalization time is calculated and characterizes the non-equilibrium state as a function of laser pulse duration. A novel thermal criterion is proposed for damage definition based on the electron and phonon energies. The calculated damage thresholds are compared with recent experimental findings. An analysis of other criteria (classical optical breakdown and thermal) is also performed.

Author:
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Category : Aeronautics
Languages : en
Pages : 836

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Author:
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ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 854

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Author: Karsten König
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110383500
Category : Science
Languages : en
Pages : 360

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Nanostructuring of materials is a task at the heart of many modern disciplines in mechanical engineering, as well as optics, electronics, and the life sciences. This book includes an introduction to the relevant nonlinear optical processes associated with very short laser pulses for the generation of structures far below the classical optical diffraction limit of about 200 nanometers as well as coverage of state-of-the-art technical and biomedical applications. These applications include silicon and glass wafer processing, production of nanowires, laser transfection and cell reprogramming, optical cleaning, surface treatments of implants, nanowires, 3D nanoprinting, STED lithography, friction modification, and integrated optics. The book highlights also the use of modern femtosecond laser microscopes and nanoscopes as novel nanoprocessing tools.

Author: Sudipta Bera
Publisher: LAP Lambert Academic Publishing
ISBN: 9783838363769
Category : Interferometry
Languages : en
Pages : 148

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A novel femtosecond micromachining workstation that permits real-time measurement of ablation depth and transient reflectivity is demonstrated. This instrumentation is used to characterize two processes: micromachining of thin metal films, and laser induced forward transfer (LIFT). Spectral interferometry was incorporated in a femtosecond micromachining system to enable real-time visualization of micromachined features as they are written into thin metal films-low energy(pJ) femtosecond oscillator pulses are used to probe the sample as it is cut by high energy (uJ) pulses. Sub-wavelength depths are readily resolved using this technique, making it possible to monitor the integrity of micromachined structures as they are created. This technique can also be employed to characterize interesting processes such as laser induced forward transfer (LIFT) of thin metal films. LIFT essentially involves using a pulsed laser to pattern a structure by deposition as opposed to ablation. Using modest numerical apertures (0.65 or less) we have been able to produce submicron features using this method of femtosecond pulsed laser deposition.

Author: National Research Council Canada
Publisher: NRC Research Press
ISBN: 9780660190280
Category : Computers
Languages : en
Pages : 354

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Book Description
The 17th annual International Symposium on High Performance Systems and Applications (HPCS 2003) and the first OSCAR Symposium were held in Sherbrooke, Quebec Canada, May 11-14, 2003. The proceedings cover various areas of High Performance Computing, from specific scientific applications to computer architecture. OSCAR is an Open Source clustering software suite for building, maintaining, and using high performance clusters.

Author: Detlev Ristau
Publisher: CRC Press
ISBN: 1439872163
Category : Technology & Engineering
Languages : en
Pages : 556

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Dedicated to users and developers of high-powered systems, Laser-Induced Damage in Optical Materials focuses on the research field of laser-induced damage and explores the significant and steady growth of applications for high-power lasers in the academic, industrial, and military arenas. Written by renowned experts in the field, this book concentrates on the major topics of laser-induced damage in optical materials and most specifically addresses research in laser damage that occurs in the bulk and on the surface or the coating of optical components. It considers key issues in the field of high-power laser coatings, factoring in the effects of contamination and providing insight into typical application areas. Become Familiar with the Key Areas of Modern Photonics The text first provides a basic understanding of theoretical and experimental methods and then summarizes the current progress, strategies, and improvements occurring within the field of laser-induced damage. Divided into four sections, this book outlines apparent trends in modeling, and discusses measurement and evaluation techniques for laser damage thresholds in the context of international standardization and scaling laws for damage thresholds. This seminal work: Covers the major aspects of laser damage Considers all important aspects in industry and research Reviews laser damage effects in material and surfaces Contains chapters contributed by leading scientists in the field Laser-Induced Damage in Optical Materials details a variety of fundamental investigations in laser-induced damage mechanisms and functions as a valuable reference for researchers and producers of laser components, laser and photonics engineers and scientists, as well as users of laser technology and thin film optics.

Author: Alexandros Mouskeftaras
Publisher:
ISBN:
Category :
Languages : en
Pages : 182

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