The invention ofthe laser 25years ago resulted in powerfullight sources which led to the observation of unexpected and striking phenomena. New fields of science such as holography and nonlinear optics developed constituting the basis of this volume. The classical principle of linear superposition of light wavesdoes not hold anymore. Two laser beams crossing in a suitable material may produce a set of new beams with different directions and frequencies. The interaction of light waves can be understood by considering the optical grating structures which develop in the overlap region. The optical properties of matter become spatially modulated in the interference region of two light waves. Permanent holographic gratings have been produced in this way by photographic processes for many years. In contrast, dynamic or transient gratings disappear after the inducing light source, usually a laser, has been switched off. The grating amplitude is controlled by the light intensity. Dynamic gratings have been induced in a large number ofsolids, liquids, and gases, and are detected by diffraction, 'forced light scattering' of a third probing beam, or by self-diffraction of the light waves inducing the grating. The combined interference and diffraction effect corresponds to four-wave mixing (FWM) in the language of nonlinear optics. The process is called degenerate ifthe frequenciesofthe three incident wavesand the scattered wave are equal. Degenerate four-wave mixing (DFWM) is a simple method to achieve phase conjugation, i.e. to generate a wave which propagates time reversed with respect to an incident wave.

The optically pumped laser has made an enormous contribution to research in the part of the electromagnetic spectrum known as the far infrared, or submillimetre region. I hope that this book will be useful to both practising and prospective workers in the field, since it contains an up-to-date catalogue of measurements of the main properties of submillimetre lasers as well as an introductory review of the measurement techniques themselves. Wavelength and frequency measurements have been exhaustively compiled (in Part II of this book) along with molecule and pump identification. Part I contains a short review of the relevant measurement techniques in each of these areas and, in addition, a review of power measurements. Working in this field, as in any other, one's satisfaction is determined largely by the colleagues one has and the friends one makes along the way. I am very grateful to Dr G. Dodel, Dr L. C. Robinson and Dr G. F. Brand for introducing me to the field. Dr I. S. Falconer and Dr P. A. Krug have been good colleagues and friends. For this book in particular I am grateful to Dr Dodel, Dr K. M. Evenson, Dr H. Figger, Prof. M. Fourrier, P. Kempf, Dr K. J. Siemsen and Dr M. S. Tobin for their comments, and to Dr D. J. E. Knight for a great deal of help, including data from unpublished or obscure sources which he had gathered for his own compilation.

Femtosecond lasers opened up new avenue in materials processing due to its unique features of ultrashort pulse width and extremely high peak intensity. One of the most important features of femtosecond laser processing is that strong absorption can be induced even by materials which are transparent to the femtosecond laser beam due to nonlinear multiphoton absorption. The multiphoton absorption allows us to perform not only surface but also three-dimensionally internal microfabrication of transparent materials such as glass. This capability makes it possible to directly fabricate three-dimensional microfluidics, micromechanics, microelectronics and microoptics embedded in the glass. Further, these microcomponents can be easily integrated in a single glass microchip by the simple procedure using the femtosecond laser. Thus, the femtosecond laser processing provides some advantages over conventional methods such as traditional semiconductor processing or soft lithography for fabrication of microfluidic, optofludic and lab-on-a-chip devices and thereby many researches on this topic are currently being carried out. This book presents a comprehensive review on the state of the art and future prospects of femtosecond laser processing for fabrication of microfluidics and optofludics including principle of femtosecond laser processing, detailed fabrication procedures of each microcomponent and practical applications to biochemical analysis.

This volume includes a collection of papers presented in Symposium TT, Laser-Material Interactions at Micro/Nanoscales, at the Spring 2011 Materials Research Society Meeting held April 2011 in San Francisco, California. Laser-material interactions are of fundamental importance in a wide range of materials-related research and areas of technology, including green energy, photonics, electronics, environmental studies, biomedical imaging, medical treatment, and optical spectroscopy. This symposium provided an interdisciplinary forum for scientists and engineers from different fields to discuss the physical, chemical, thermal, and mechanical phenomena that occur during laser-material interactions at micro and nano scales. Research addressing new materials, processes, structures, and surfaces synthesized by these methods for emerging fields was discussed. The symposium was well attended and received a large number of abstract submissions in the areas of ultrafast laser processing, laser ablation and deposition, process controls, nanomaterials, surface modification, laser materials interactions, polymerization, lithography, and novel approaches in laser processing.

This book shows an update in the field of micro/nano fabrications techniques of two and three dimensional structures as well as ultimate three dimensional characterization methods from the atom range to the micro scale. Several examples are presented showing their direct application in different technological fields such as microfluidics, photonics, biotechnology and aerospace engineering, between others. The effects of the microstructure and topography on the macroscopic properties of the studied materials are discussed, together with a detailed review of 3D imaging techniques.

Terahertz science and technology is attracting great interest due to its application in a wide array of fields made possible by the development of new and improved terahertz radiation sources and detectors. This book focuses on the development and characterization of one such source - namely the semi-large aperture photoconducting (PC) antenna fabricated on Fe-doped bulk Ga0.69In0.31As substrate. The high ultrafast carrier mobility, high resistivity, and subpicosecond carrier lifetime along with low bandgap make Ga0.69In0.31As an excellent candidate for PC antenna based THz emitter that can be photoexcited by compact Yb-based multiwatt laser systems for high power THz emission. The research is aimed at evaluating the impact of physical properties of a semi-large aperture Ga0.69In0.31As PC antenna upon its THz generation efficiency, and is motivated by the ultimate goal of developing a high-power terahertz radiation source for time-domain terahertz spectroscopy and imaging systems.

This thesis provides deep insights into currently controversial questions in laser filamentation, a highly complex phenomenon involving nonlinear optical effects and plasma physics. First, based on the concrete picture of a femtosecond laser beam which self-pinches its radial intensity distribution, the thesis delivers a novel explanation for the remarkable and previously unexplained phenomenon of pulse self-compression in filaments. Moreover, the work addresses the impact of a non-adiabatic change of both nonlinearity and dispersion on such an intense femtosecond pulse transiting from a gaseous dielectric material to a solid one. Finally, and probably most importantly, the author presents a simple and highly practical theoretical approach for quantitatively estimating the influence of higher-order nonlinear optical effects in optics. These results shed new light on recent experimental observations, which are still hotly debated and may completely change our understanding of filamentation, causing a paradigm change concerning the role of higher-order nonlinearities in optics.

Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femtosecond lasers) and parametric oscillators, coherent matter waves, Doppler-free Fourier spectroscopy with optical frequency combs, interference spectroscopy, quantum optics, the interferometric detection of gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

The transmission speed of data communication systems is forecast to increase exponentially over the next decade. Development of both Si-based high-speed drivers as well as III-V-semiconductor-based high-speed vertical cavity surface emitting lasers (VCSELs) are prerequisites for future ultrahigh data-rate systems. This thesis presents: - a survey of the present state of the art of VCSELs - a systematic investigation of the various effects limiting present VCSELs - a catalogue of solutions to overcome present limits - detailed progress in modelling, fabricating and testing the currently most advanced VCSELs at the two commercially most important wavelengths.

This book features tutorial-like chapters on ultrafast intense laser science by world-leading scientists who are active in the rapidly developing interdisciplinary research field. It is written to give a comprehensive survey of all the essential aspects of ultrafast intense laser science. The volume covers theories of atoms and molecules in intense laser fields, high intensity physics scaled to long wavelength, pulse shaping techniques, non-linear optics in the XUV region, ultrafast X-ray spectroscopy, quantum emission and applications, filamentation, and ultraintense-laser matter interaction.

This book introduces laser drilling processes including modelling, quality assessment of drilled holes, and laser drilling applications. It provides insights into the laser drilling process and relation among the drilling parameters pertinent to improved end product quality. This book is written for engineers and scientists working on laser machining, particularly laser drilling.

The growth of regularity from disorder, the evolution from the simple towards the complex, and the spontaneous formation of spatio temporal patterns in general are questions which intrigue everybody. This has been one of the hasic philosophical topics from ancient to modern times. Is nature able to create something fundamentally new by itself? If yes, how does this creation occurs? Or does nature only reproduce something which was already encoded in it, from the very beginning? This remained a topic exclusively for philoso phers until very recently, and it was only a few decades a. go that physicists started to convert this seemingly purely philosophical subject into a scientific discipline: a scientific discipline like other scientific disciplines, where one re lies on formulas and equations, on nunlerical simulations, and on laboratory experiments. This book is not about general questions related to pattern formation and self organization in nature. It is about spontaneous patterns in just one part of nature in nonlinear optical systems, and, more precisely, in nonlinear optical resonators. Nonlinear optical systems represent a small part of nature, hut a very representative part: one can observe here nearly all the known symmetries of patterns, one can generate nearly all known types of localized strlictlires and one can realize nearly all known spatial instabilities and spatial bifurcations.

Miniaturization and high precision are rapidly becoming a requirement for many industrial processes and products. As a result, there is greater interest in the use of laser microfabrication technology to achieve these goals. This book composed of 16 chapters covers all the topics of laser precision processing from fundamental aspects to industrial applications to both inorganic and biological materials. It reviews the sate of the art of research and technological development in the area of laser processing.

The growth of Internet traf?c in recent years surpassed the prediction of one decade ago. Data stream in individual countries already reached terabit/s level. To cope with the petabit class demands of traf?c in coming years the communication engineers are required to go beyond the incremental improvement of today's technology. A most promising breakthrough would be the introduction of modulation f- mats enabling higher spectral ef?ciency than that of binary on-off keying scheme, virtually the global standard of ?ber-optic communication systems. In wireless communication systems, techniques of high spectral density modulation have been well developed, but the required techniques in optical frequency domain are much more complicated because of the heavier ?uctuation levels. Therefore the past trials of coherent optical modulation/detection schemes were not successful. However, the addition of high-speed digital signal processing technology is the fundam- tal difference between now and two decades ago, when trials of optical coherent communication systems were investigated very seriously. This approach of digital coherent technology has attracted keen interest among communication specialists, as indicated by the rapid increase in the pioneering presentations at the post-deadline sessions of major international conferences. For example, 32 terabit/s transmission in a ?ber experiment based on this technology was reported in post-deadline session of Optical Fiber Communication Conference (OFC) 2009. The advancement of the digital coherent technologies will inevitably affect the network architecture in terms of the network resource management for the new generation photonic networks, rather than will simply provide with huge transmission capacity.

This work addresses time-delay in complex nonlinear systems and, in particular, its applications in complex networks; its role in control theory and nonlinear optics are also investigated. Delays arise naturally in networks of coupled systems due to finite signal propagation speeds and are thus a key issue in many areas of physics, biology, medicine, and technology. Synchronization phenomena in these networks play an important role, e.g., in the context of learning, cognitive and pathological states in the brain, for secure communication with chaotic lasers or for gene regulation. The thesis includes both novel results on the control of complex dynamics by time-delayed feedback and fundamental new insights into the interplay of delay and synchronization. One of the most interesting results here is a solution to the problem of complete synchronization in general networks with large coupling delay, i.e., large distances between the nodes, by giving a universal classification of networks that has a wide range of interdisciplinary applications.

The technology surrounding the design and fabrication of optical microresonators has matured to a point where there is a need for commercialization. Consequently, there is a need for device research involving more advanced architectures and more esoteric operating principles. Photonic Microresonator Research and Applications explores advances in the fabrication process that enable nanometer waveguide separations, exceptionally smooth surfaces essential to reach Q factors in the order of 106- 108 and high index contrast materials.

The ionization of atoms and molecules in strong laser fields is an active field in modern physics and has versatile applications in such as attosecond physics, X-ray generation, inertial confined fusion (ICF), medical science and so on. "Classical Trajectory Perspective of Atomic Ionization in Strong Laser Fields" covers the basic concepts in this field and discusses many interesting topics using the semiclassical model of classical trajectory ensemble simulation, which is one of the most successful ionization models and has the advantages of a clear picture, feasible computing and accounting for many exquisite experiments quantitatively. The book also presents many applications of the model in such topics as the single ionization, double ionization, neutral atom acceleration and other timely issues in strong field physics, and delivers useful messages to readers with presenting the classical trajectory perspective on the strong field atomic ionization. The book is intended for graduate students and researchers in the field of laser physics, atom molecule physics and theoretical physics. Dr. Jie Liu is a professor of Institute of Applied Physics and Computational Mathematics, China and Peking University.

This book describes the basic mechanisms, theory, simulations and technological aspects of Laser processing techniques. It covers the principles of laser quenching, welding, cutting, alloying, selective sintering, ablation, etc. The main attention is paid to the quantitative description. The diversity and complexity of technological and physical processes is discussed using a unitary approach. The book aims on understanding the cause-and-effect relations in physical processes in Laser technologies. It will help researchers and engineers to improve the existing and develop new Laser machining techniques. The book addresses readers with a certain background in general physics and mathematical analysis: graduate students, researchers and engineers practicing laser applications.

Digital holography is an emerging field of new paradigm in general imaging applications. The book presents an introduction to the theoretical and numerical principles and reviews the research and development activities in digital holography, with emphasis on the microscopy techniques and applications. Topics covered include the general theory of diffraction and holography formations, and practical instrumentation and experimentation of digital holography. Various numerical techniques are described that give rise to the unique and versatile capabilities of digital holography. Representative special techniques and applications of digital holography are discussed. The book is intended for researchers interested in developing new techniques and exploring new applications of digital holography.

The PUILS series delivers up-to-date reviews of progress in Ultrafast Intense Laser Science, a newly emerging interdisciplinary research field spanning atomic and molecular physics, molecular science, and optical science, which has been stimulated by the recent developments in ultrafast laser technologies. Each volume compiles peer-reviewed chapters authored by researchers at the forefront of each their own subfields of UILS. Every chapter begins with an overview of the topics to be discussed, so that researchers unfamiliar to the subfield, as well as graduate students, can grasp the importance and attractions of the research topic at hand; these are followed by reports of cutting-edge discoveries. This seventh volume covers a broad range of topics from this interdisciplinary research field, focusing on the ionization of atoms and molecules, ultrafast responses of protons and electrons within a molecule, molecular alignment, high-order harmonics and attosecond pulse generation, and acceleration of electrons and ions in laser plasmas.

Glasses containing metallic nanoparticles exhibit very promising linear and nonlinear optical properties, mainly due to the surface plasmon resonances (SPRs) of the nanoparticles. The spectral position in the visible and near-infrared range and polarization dependence of the SPR arecharacteristically determined by the nanoparticles shapes.

The focus of "Ultra-Short Pulsed Laser Engineered Metal-Glass Nanocomposites" is the interaction of intense ultra-short laser pulses with glass containing silver nanoparticles embedded in soda-lime glass, and nanostructural modifications in metal-glass nanocomposites induced by such laser pulses. In order to provide a comprehensive physical picture of the processes leading to laser-induced persistent shape transformation of the nanoparticles, series of experimental results investigating the dependences of laser assisted shape modifications of nanoparticles with laser pulse intensity, excitation wavelength, temperature are considered. In addition, the resulting local optical dichroism allows producing very flexibly polarizing optical (sub-) microstructures with well-specified optical properties. The achieved considerable progress towards technological application of this technique, in particular also for long-term optical data storage, is also discussed.

This book is the result of two decades of research work which started with an accidental observation. One of my students, Dipl. phys. Volkmar Lenz, - ticed that the speckle pattern of laser light scattered by a cuvette containing diluted milk performed a strange motion every time he came near the cuvette with his thumb. After thinkingabout this e?ect we came to the conclusion that this motion can only be caused by scatteringparticles with di?erent velocities, as in the case of the di?raction pattern of an optical grating: A linear motion of the grating does not change the pattern whereas a rotation of the grating does. The observed speckle motion could then be explained qualitatively as produced by the inhomogeneous velocity of the convection within the cuvette which was produced by the heat of the thumb. The theoretical treatment of this e?ect revealed that the velocity gradient of the light scattering medium is responsible for the speckle motion. The idea to use this e?ect for developingmeasurement techniques for velocity gradients arose almost immediately. For that purpose we had to develop not only experimental set-ups to measure the pattern velocity but also the theory which describes the connection between this velocity and the velocity gradient. The result of this work together with the description of a method developed by another group forms the contents of this book. I am indebted to the students who worked in my laboratory and developed the measurement techniques. These were, in temporal order, Dr.

New chapters and updates highlight the second edition of Laser Safety: Tools and Training. This text provides background information relating to lasers and laser safety, and examines the components of laser work and laser safety from a different perspective. Written by a working laser safety officer, the book considers ways to keep users, as well as those around them, safe. The author encourages readers to think beyond protective eyewear. As it relates to safety, he determines that if eyewear is required, then the laser system is not ideal. This book factors in optics, the vibration elements of the optical table, the power meter, and user training, elements that are not commonly considered in the context of laser safety. It presents ways for users to evaluate the hazards of any laser procedure and ensure that they are following documented laser safety standards. The material serves as a fundamental means or road map for laser users seeking to utilize the safest system possible. What's New in the Second Edition: The second edition provides an inclusion of the Z136.8 Research Laser Standard, and offers updates and an explanation of eye exposure limits (MPE), presents new cases studies, and presents practical example images. It includes coverage of, laser lab design lessons, addresses user facility challenges and laser disposal. Presents case studies of real accidents, preventive measures, and templates for documenting potential laser risks and attendant safety measures Reviews factors often overlooked when one is setting up a laser lab Demonstrates how to investigate a laser incident This text which includes fundamental laser and laser safety information, as well as critical laser use information, is appropriate for both the novice and the seasoned professional.

How do laser beams propagate? Innovative discoveries involving laser beams and their propagation properties are at the heart of Laser Beam Propagation: Generation and Propagation of Customized Light. This book captures the essence of laser beam propagation. Divided into three parts, it explores the fundamentals of how laser beams propagate, and provides novel methods to describe and characterize general laser beams. Part one covers the physical optics approach to the propagation of optical waves, the concept of plane waves, the mathematical description of diffraction and Gaussian optics, and adapting the concepts to the single photon level. The book explains the parallels between the paraxial propagation of light beams and the Schroedinger equation in quantum mechanics, and delves into the description of paraxial optics by means of state vectors and operators. It also discusses classical optics and quantum entanglement. Part two focuses on the application of modal decomposition to the characterization of laser beams, and provides a characterization of time domain pulses. It discusses tools for the temporal characterization of laser beams, the generation of arbitrary laser beams with digital holograms, and the use of spatial light modulators to display reconfigurable digital holograms capable of modifying and shaping laser beams. It also covers various techniques and the control of the polarization properties of light. Part three defines the most commonly generated shaped light, flat-top beams, outlining their propagation rules as well as the means to create them in the laboratory. It also highlights Helmholtz-Gauss beams, vector beams, and low coherence laser beams. The text presents the concepts of coherence theory and applies this to the propagation of low coherence optical fields. It also considers the recent developments in orbital angular momentum carrying fields, touches on basics properties, definitions and applications, and brings together the classical and quantum concepts of spatial modes of light.