Population Inversions in an Expanding Gas
Population Inversions in an Expanding Gas

Author: John David Anderson (Jr.)

Publisher:

Published: 1971

Total Pages: 80

ISBN-13:

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It is well established that population inversions between the (001) and (100) vibrational energy levels of CO2 can be created by rapid expansions of CO2-N2-H2O or He mixtures through supersonic nozzles. New experimental results are presented for such inversions. These experiments were conducted in both the 3-Megawatt Arc Tunnel and the 12.7 cm Shock Tunnel at the Naval Ordnance Laboratory. The results support previously published theoretical predictions obtained with a numerical, time-dependent, nonequilibrium nozzle flow analysis employing a simplified vibrational kinetic model. This theory is also compared with experimental data obtained by other investigators. (Author).

A Time-dependent Quasi-one-dimensional Analysis of Population Inversions in an Expanding Gas
A Time-dependent Quasi-one-dimensional Analysis of Population Inversions in an Expanding Gas

Author: John David Anderson (Jr.)

Publisher:

Published: 1969

Total Pages: 70

ISBN-13:

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A time-dependent technique for the numerical solution of convergent-divergent, nonequilibrium nozzle flows was used to analyze the rapid, vibrational nonequlibrium, supersonic expansion of CO2-N2-H2O and CO2-N2-He mixtures, wherein the finite rate molecular energy transfer processes can result in a population inversion between the (001) and (100) vibrational energy levels of CO2. Results for such population inversions are presented. Among these, a comparison was made between the present results and the recent results of Basov et al; this comparison indicates that Basov's calculations overestimate the population inversion in an expanding mixture of CO2 and N2. In addition, results are presented from a series of numerical experiments conducted to assess the validity of several simplified methods for computing population inversions. (Author).

Vibrational Population Inversions Within Normal Shock Waves in CO2-N2-He Mixtures
Vibrational Population Inversions Within Normal Shock Waves in CO2-N2-He Mixtures

Author: John David Anderson (Jr.)

Publisher:

Published: 1970

Total Pages: 74

ISBN-13:

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Numerical solutions are given for vibrational population inversions created in CO2-N2-He mixtures due to shock wave heating of a cold gas. The results indicate that population inversions between the (040) and (001) energy levels of CO2 and, to a lesser degree, between the (200) and (001) levels, can be created in the vibrational nonequilibrium flow behind a normal shock front. The properties of these inversions as a possible laser medium are assessed; the results indicate that the laser properties of this shock-induced nonequilibrium flow are not as promising as those of lasers operating on the principle of rapid expansions. (Author).

Gasdynamic Lasers: An Introduction
Gasdynamic Lasers: An Introduction

Author: John D. Jr. Anderson

Publisher: Elsevier

Published: 2012-12-02

Total Pages: 193

ISBN-13: 0323160441

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Gasdynamic Lasers: An Introduction is a 12-chapter introductory text to major development generations of gasdynamic lasers, focusing on their underlying physical and fundamental aspects. The opening chapters discuss the basic detailed physical phenomena that ultimately are responsible for producing gasdynamic laser action and the methods of calculating the performance of these devices. These topics are followed by a chapter on confirmation of the performance calculations through arc and shock tunnel experiments. The discussion then shifts to vibrational relaxation process behind normal shock waves in CO2-N2-He mixtures and assesses their population inversions occurring in the nonequilibrium flow. Other chapters explore the concepts of downstream mixing and optical cavity in gasdynamic lasers, as well as the laser beam extracted from these devices. A systematic study of aerodynamic windows that use supersonic flow across the aperture is presented in the concluding chapters, along with the phenomena associated with gasdynamic laser diffusers. This introductory text will be of great value to professional scientists and engineers, as well as to students and workers in the field who are interested in interdisciplinary applied science.

Laser Physics and Technology
Laser Physics and Technology

Author: Pradeep Kumar Gupta

Publisher: Springer

Published: 2014-11-06

Total Pages: 352

ISBN-13: 8132220005

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The book, ‘Laser Physics and Technology’, addresses fundamentals of laser physics, representative laser systems and techniques, and some important applications of lasers. The present volume is a collection of articles based on some of the lectures delivered at the School on ‘Laser Physics and Technology’ organized at Raja Ramanna Centre for Advanced Technology during March, 12-30, 2012. The objective of the School was to provide an in-depth knowledge of the important aspects of laser physics and technology to doctoral students and young researchers and motivate them for further work in this area. In keeping with this objective, the fourteen chapters, written by leading Indian experts, based on the lectures delivered by them at the School, provide along with class room type coverage of the fundamentals of the field, a brief review of the current status of the field. The book will be useful for doctoral students and young scientists who are embarking on a research in this area as well as to professionals who would be interested in knowing the current state of the field particularly in Indian context.

Principles of Lasers
Principles of Lasers

Author: Orazio Svelto

Publisher: Springer Science & Business Media

Published: 2013-04-17

Total Pages: 612

ISBN-13: 1475762666

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This book is motivated by the very favorable reception given to the previous editions as well as by the considerable range of new developments in the laser field since the publication of the third edition in 1989. These new developments include, among others, quantum-well and muitiple-quantum-welliasers, diode-pumped solid-state lasers, new concepts for both stable and unstable resonators, femtosecond lasers, ultra-high-brightness lasers, etc. This edition thus represents a radically revised version of the preceding edition, amounting essentially to a new book in its own right. However, the basic aim has remained the same, namely to provide a broad and unified description of laser behavior at the simplest level which is compatible with a correct physical understanding. The book is therefore intended as a textbook for a senior-level or first-year graduate course and/or as a reference book. The most relevant additions or changes to this edition can be summarized as follows: 1. A much-more detailed description of Amplified Spontaneous Emission has been given (Chapter 2) and a novel simplified treatment of this phenomenon, both for homogeneous and inhomogeneous lines, has been introduced (Appendix C). 2. A major fraction of a new chapter (Chapter 3) is dedicated to the interaction of radiation with semiconductor media, either in a bulk form or in a quantum-confined structure (quantum-well, quantum-wire and quantum dot). 3.

CO2 Lasers Effects and Applications
CO2 Lasers Effects and Applications

Author: W Duley

Publisher: Elsevier

Published: 2012-12-02

Total Pages: 444

ISBN-13: 0323150136

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CO2 Lasers: Effects and Applications examines and summarizes the important applications of the device in different areas of study like physics, chemistry, and engineering. In some parts of the book, the reader is assumed to be knowledgeable in university level mathematics or some specialized area in physics or chemistry. The book consists of 10 chapters where the first two establish the general concepts on lasers and CO2 lasers, respectively. Chapter 3 takes the reader further and presents a comprehensive review of optical components for use such as detectors, windows, and mirrors. Because the CO2 laser is mostly used as a heat source, the theory of laser-surface heating is relevant in the discussion. This theory is presented in Chapter 4. Chapters 5 and 6 meanwhile present a summary of observations on cutting, welding, and some related topics. The following chapters discuss the different applications of CO2 lasers in different areas and processes. Some of these applications include in the generation of thermal effect, laser deposition of thin films, spectroscopy, laser photochemistry, and meteorology and communication systems. The text is a good source of reference to both students and scientists in the areas of physics, chemistry, and engineering.