Theoretical Femtosecond Physics


Book Description

This volume offers theoretical investigations of atoms and molecules interacting with pulsed or continuous wave lasers. Theoretical background is included, and the text incorporates several exercises. Additional calculations are performed in the appendices.




Femtosecond Laser Pulses


Book Description

This is the second edition of this advanced textbook written for scientists who require further training in femtosecond science. Four years after pub- cation of the ?rst edition, femtosecond science has overcome new challenges and new application ?elds have become mature. It is necessary to take into account these new developments. Two main topics merged during this period that support important scienti?c activities: attosecond pulses are now gen- ated in the X-UV spectral domain, and coherent control of chemical events is now possible by tailoring the shape of femtosecond pulses. To update this advanced textbook, it was necessary to introduce these ?elds; two new ch- ters are in this second edition: “Coherent Control in Atoms, Molecules, and Solids”(Chap.11)and“AttosecondPulses”(Chap.12)withwell-documented references. Some changes, addenda, and new references are introduced in the ?rst edition’s ten original chapters to take into account new developments and updatethisadvancedtextbookwhichistheresultofascienti?cadventurethat started in 1991. At that time, the French Ministry of Education decided that, in view of the growing importance of ultrashort laser pulses for the national scienti?c community, a Femtosecond Centre should be created in France and devoted to the further education of scientists who use femtosecond pulses as a research tool and who are not specialists in lasers or even in optics.




Theoretical Femtosecond Physics


Book Description

Theoretical investigations of atoms and molecules interacting with pulsed or continuous wave lasers up to atomic field strengths on the order of 10^16 W/cm2 are leading to an understanding of many challenging experimental discoveries. This book deals with the basics of femtosecond physics and goes up to the latest applications of new phenomena. The book presents an introduction to laser physics with mode-locking and pulsed laser operation. The solution of the time-dependent Schrödinger equation is discussed both analytically and numerically. The basis for the non-perturbative treatment of laser-matter interaction in the book is the numerical solution of the time-dependent Schrödinger equation. The light field is treated classically, and different possible gauges are discussed. Physical phenomena, ranging from Rabi-oscillations in two-level systems to the ionization of atoms, the generation of high harmonics, the ionization and dissociation of molecules as well as the control of chemical reactions are presented and discussed on a fundamental level. In this way the theoretical background for state of the art experiments with strong and short laser pulses is given. The text is augmented by more than thirty exercises, whose worked-out solutions are given in the last chapter. Some detailed calculations are performed in the appendices. Furthermore, each chapter ends with references to more specialized literature.




Femtosecond Laser Micromachining


Book Description

Femtosecond laser micromachining of transparent material is a powerful and versatile technology. In fact, it can be applied to several materials. It is a maskless technology that allows rapid device prototyping, has intrinsic three-dimensional capabilities and can produce both photonic and microfluidic devices. For these reasons it is ideally suited for the fabrication of complex microsystems with unprecedented functionalities. The book is mainly focused on micromachining of transparent materials which, due to the nonlinear absorption mechanism of ultrashort pulses, allows unique three-dimensional capabilities and can be exploited for the fabrication of complex microsystems with unprecedented functionalities.This book presents an overview of the state of the art of this rapidly emerging topic with contributions from leading experts in the field, ranging from principles of nonlinear material modification to fabrication techniques and applications to photonics and optofluidics.




Femtosecond Laser Filamentation


Book Description

This book attempts to give a discussion of the physics and current and potential applications of the self-focusing of an intense femtosecond laser pulse in a tra- parent medium. Although self-focusing is an old subject of nonlinear optics, the consequence of self-focusing of intense femtosecond laser pulses is totally new and unexpected. Thus, new phenomena are observed, such as long range lam- tation, intensity clamping, white light laser pulse, self-spatial ltering, self-group phase locking, self-pulse compression, clean nonlinear uorescence, and so on. Long range propagation at high intensity, which is seemingly against the law of diffraction, is probably one of the most exciting consequences of this new sub- eld of nonlinear optics. Because the intensity inside the lament core is high, new ways of doing nonlinear optics inside the lament become possible. We call this lamentation nonlinear optics. We shall describe the generation of pulses at other wavelengths in the visible and ultraviolet (UV) starting from the near infrared pump pulse at 800 nm through four-wave-mixing and third harmonic generation, all in gases. Remotely sensing uorescence from the fragments of chemical and biological agents in all forms, gaseous, aerosol or solid, inside the laments in air is demonstrated in the labo- tory. The results will be shown in the last part of the book. Through analyzing the uorescence of gas molecules inside the lament, an unexpected physical process pertaining to the interaction of synchrotron radiation with molecules is observed.




Femtosecond Laser Spectroscopy


Book Description

The embryonic development of femtoscience stems from advances made in the generation of ultrashort laser pulses. Beginning with mode-locking of glass lasers in the 1960s, the development of dye lasers brought the pulse width down from picoseconds to femtoseconds. The breakthrough in solid state laser pulse generation provided the current reliable table-top laser systems capable of average power of about 1 watt, and peak power density of easily watts per square centimeter, with pulse widths in the range of four to eight femtoseconds. Pulses with peak power density reaching watts per square centimeter have been achieved in laboratory settings and, more recently, pulses of sub-femtosecond duration have been successfully generated. As concepts and methodologies have evolved over the past two decades, the realm of ultrafast science has become vast and exciting and has impacted many areas of chemistry, biology and physics, and other fields such as materials science, electrical engineering, and optical communication. In molecular science the explosive growth of this research is for fundamental reasons. In femtochemistry and femtobiology chemical bonds form and break on the femtosecond time scale, and on this scale of time we can freeze the transition states at configurations never before seen. Even for n- reactive physical changes one is observing the most elementary of molecular processes. On a time scale shorter than the vibrational and rotational periods the ensemble behaves coherently as a single-molecule trajectory.




Ultrafast Phenomena in Molecular Sciences


Book Description

This book presents the latest developments in Femtosecond Chemistry and Physics for the study of ultrafast photo-induced molecular processes. Molecular systems, from the simplest H2 molecule to polymers or biological macromolecules, constitute central objects of interest for Physics, Chemistry and Biology, and despite the broad range of phenomena that they exhibit, they share some common behaviors. One of the most significant of those is that many of the processes involving chemical transformation (nuclear reorganization, bond breaking, bond making) take place in an extraordinarily short time, in or around the femtosecond temporal scale (1 fs = 10-15 s). A number of experimental approaches - very particularly the developments in the generation and manipulation of ultrashort laser pulses - coupled with theoretical progress, provide the ultrafast scientist with powerful tools to understand matter and its interaction with light, at this spatial and temporal scale. This book is an attempt to reunite some of the state-of-the-art research that is being carried out in the field of ultrafast molecular science, from theoretical developments, through new phenomena induced by intense laser fields, to the latest techniques applied to the study of molecular dynamics.




Femtosecond Optical Frequency Comb: Principle, Operation and Applications


Book Description

Over the last few years, there has been a convergence between the fields of ultrafast science, nonlinear optics, optical frequency metrology, and precision laser spectroscopy. These fields have been developing largely independently since the birth of the laser, reaching remarkable levels of performance. On the ultrafast frontier, pulses of only a few cycles long have been produced, while in optical spectroscopy, the precision and resolution have reached one part in Although these two achievements appear to be completely disconnected, advances in nonlinear optics provided the essential link between them. The resulting convergence has enabled unprecedented advances in the control of the electric field of the pulses produced by femtosecond mode-locked lasers. The corresponding spectrum consists of a comb of sharp spectral lines with well-defined frequencies. These new techniques and capabilities are generally known as “femtosecond comb technology. ” They have had dramatic impact on the diverse fields of precision measurement and extreme nonlinear optical physics. The historical background for these developments is provided in the Foreword by two of the pioneers of laser spectroscopy, John Hall and Theodor Hänsch. Indeed the developments described in this book were foreshadowed by Hänsch’s early work in the 1970s when he used picosecond pulses to demonstrate the connection between the time and frequency domains in laser spectroscopy. This work complemented the advances in precision laser stabilization developed by Hall.




Femtosecond Laser-Matter Interaction


Book Description

This is the first comprehensive treatment of the interaction of femtosecond laser pulses with solids at nonrelativistic intensity. It connects phenomena from the subtle atomic motion on the nanoscale to the generation of extreme pressure and temperature in the interaction zone confined inside a solid. The femtosecond laser-matter interaction has already found numerous applications in industry, medicine, and materials science. However, there is no consensus on the interpretation of related phenomena. With mathematics kept to a minimum, this is a highly engaging and readable treatment for students and researchers in science and engineering. The book avoids complex mathematical formulae, and hence the content is accessible to nontechnical readers. Useful summaries after each chapter provide compressed information for quick estimates of major parameters in planned or performed experiments. The book connects the basic physics of femtosecond laser-solid interactions to a broad range of applications. Throught the text, basic assumptions are derived from the first principles, and new results and ideas are presented. From such analyses, a qualitative and predictive framework for the field emerges, the impact of which on applications is also discussed.




Femtosecond Technology for Technical and Medical Applications


Book Description

A comprehensive overview of the principles and applications of femtosecond lasers, especially applied to medicine and to production technology. The advantages and problems of ultrashort laser pulses are discussed in more detail in the context of applications in the micro-machining of technical materials such as drilling, surface structuring and cutting, in medical use like dental, ophthalmologic, neurological and otolaryngological applications, in metrology, and in the generation of x-rays. Safety aspects are also considered.