Download or read book Ultrafast Control of the Dynamics of Diatomic Molecules written by Daniel Walter Pinkham and published by . This book was released on 2008 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Samples of gaseous diatomic molecules are excited into rotational wavepackets by ultrashort laser pulses, and the resultant dynamics are probed in the time-domain. The preparation of non-isotropic rotational distributions of molecules in field-free conditions enables a number of strong-field physics experiments to be performed. This process, known as transient alignment, serves as the central tool for most of the work described here. First, the angle-dependent ionization rates are measured for samples of room-temperature CO. Next, the polarizability anisotropy Deltaalpha---quantity indicating how easily the electronic cloud is distorted by an applied electric field---is extracted for HBr molecules at ∼30 K, by observing the transient alignment efficiency in comparison to that of a reference molecule, N2. In a follow-up experiment, a feedback-optimized algorithm is used to improve the transient alignment process by phase-shaping the pump laser pulses, and principal control analysis is used to search for pulse-shaping parameter "knobs" that most effectively control the alignment process. We observe that a rigid-rotor model with a constant Deltaalpha is sufficient to describe the alignment dynamics. In the final section, we explore asymmetric dissociation of multiply charged ions produced by intense laser ionization in a 2-color field. By combining 800 nm and 400 nm laser pulses we produce an oscillating electric field with a controllable, periodic "up-down" asymmetry in the lab frame. This asymmetry can be used to control the relative yields of ion fragments ejected in different directions. In contrast to previous studies with 2-color fields, we utilize an independent, symmetric, ionization pulse to determine that the observed dissociation is the result of an induced directionality in the field-dressed molecules rather than transient orientation of the molecule. This asymmetry is found to be an effect of enhanced molecular ionization at a critical internuclear distance (RC > Req). This fact is further illustrated by our observation of an asymmetry in the dissociation of symmetric molecules (e.g. N3+2 → N2+ + N+). We conclude with an analysis of transient molecular orientation in 2-color fields and describe preliminary attempts to observe it.
Download or read book Molecular Dynamics in Diatomic Molecules with One and Two color Ultrafast Laser Pulses written by Vincent Tagliamonti and published by . This book was released on 2014 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantum Control of Laser Induced Dynamics of Diatomic Molecular Ions Using Shaped Intense Ultrafast Laser Pulses written by Leigh Graham and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Spectra and Dynamics of Diatomic Molecules written by Helene Lefebvre-Brion and published by Academic Press. This book was released on 2004-04-02 with total page 797 pages. Available in PDF, EPUB and Kindle. Book excerpt: And concluding with some examples of polyatomic molecule dynamics. P Students will discover that there is a fascinating world of cause-and-effect localized dynamics concealed beyond the reduction of spectra to archival molecular constants and the exact ab initio computation of molecular properties.-
Download or read book Ultrafast Dynamics Driven by Intense Light Pulses written by Markus Kitzler and published by Springer. This book was released on 2015-07-24 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book documents the recent vivid developments in the research field of ultrashort intense light pulses for probing and controlling ultrafast dynamics. The recent fascinating results in studying and controlling ultrafast dynamics in ever more complicated systems such as (bio-)molecules and structures of meso- to macroscopic sizes on ever shorter time-scales are presented. The book is written by some of the most eminent experimental and theoretical experts in the field. It covers the new groundbreaking research directions that were opened by the availability of new light sources such as fully controlled intense laser fields with durations down to a single oscillation cycle, short-wavelength laser-driven attosecond pulses and intense X-ray pulses from the upcoming free electron lasers. These light sources allowed the investigation of dynamics in atoms, molecules, clusters, on surfaces and very recently also in nanostructures and solids in new regimes of parameters which, in turn, led to the identification of completely new dynamics and methods for controlling it. Example topics covered by this book include the study of ultrafast processes in large molecules using attosecond pulses, control of ultrafast electron dynamics in solids with shaped femtosecond laser pulses, light-driven ultrafast plasmonic processes on surfaces and in nanostructures as well as research on atomic and molecular systems under intense X-ray radiation. This book is equally helpful for people who would like to step into this field (e.g. young researchers), for whom it provides a broad introduction, as well as for already experienced researchers who may enjoy the exhaustive discussion that covers the research on essentially all currently studied objects and with all available ultrafast pulse sources.
Download or read book Analysis and Control of Ultrafast Photoinduced Reactions written by Oliver Kühn and published by Springer Science & Business Media. This book was released on 2007-02-05 with total page 855 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes several years of research carried out by a collaboration of many groups on ultrafast photochemical reactions. It emphasizes the analysis and characterization of the nuclear dynamics within molecular systems in various environments induced by optical excitations and the study of the resulting molecular dynamics by further interaction with an optical field.
Download or read book Femtochemistry And Femtobiology Ultrafast Dynamics In Molecular Science written by Abderrazzak Douhal and published by World Scientific. This book was released on 2002-05-30 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains important contributions from top international scientists on the-state-of-the-art of femtochemistry and femtobiology at the beginning of the new millennium. It consists of reviews and papers on ultrafast dynamics in molecular science.The coverage of topics highlights several important features of molecular science from the viewpoint of structure (space domain) and dynamics (time domain). First of all, the book presents the latest developments, such as experimental techniques for understanding ultrafast processes in gas, condensed and complex systems, including biological molecules, surfaces and nanostructures. At the same time it stresses the different ways to control the rates and pathways of reactive events in chemistry and biology. Particular emphasis is given to biological processes as an area where femtodynamics is becoming very useful for resolving the structural dynamics from techniques such as electron diffraction, and X-ray and IR spectroscopy. Finally, the latest developments in quantum control (in both theory and experiment) and the experimental pulse-shaping techniques are described.
Download or read book Ultrafast Phenomena in Molecular Sciences written by Rebeca de Nalda and published by Springer Science & Business Media. This book was released on 2013-10-22 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Dissociation Dynamics of Molecular Ions in Ultrafast Intense Laser Fields written by Bethany Jochim and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Out of the many tools for probing molecular dynamics, intense, ultrafast laser pulses are particularly well suited for this purpose. First, these pulses have temporal durations shorter than the typical rotational and vibrational periods of molecules and therefore allow the observation of molecular dynamics on their native timescales. Further, the broad bandwidth and high peak intensities of these laser pulses can result in the excitation of many transition pathways that may interfere and enable control of dynamics. The primary focus of this work is the ultrafast laser-induced dissociation of molecular ions. We generate these ions as "fast" beam targets and study their fragmentation using a coincidence three-dimensional (3D) momentum imaging technique, which allows the measurement of all nuclear fragments, including neutrals. This approach is employed to study laser-induced processes in a variety of molecules. The goal of these efforts is not to study specific molecules but rather to use them as testing grounds to deepen our knowledge of laser-induced molecular dynamics in general. For example, we find that permanent-dipole transitions, which are commonly overlooked in the interpretation of strong-field experiments, play a key role in laser-induced dissociation of metastable NO2+ ions. General consideration of these transitions in heteronuclear molecules is important in building our understanding towards more complex molecules. Speaking of more complex systems, we have also begun investigating the laser-induced dynamics of simple hydrocarbons. Our use of molecular ion beam targets gives us the unique ability to exercise control over the initial "configuration," i.e., geometry of these molecules. Utilizing C2H2^q ion beam targets (where q is the molecular ion charge state) prepared in various initial configurations, including acetylene (HCCH), vinylidene (H2CC), and cis/trans, we have determined that this property has an immense impact on the isomerization dynamics, a finding that we anticipate will lead to future work towards deeper understanding. More broadly, this approach of probing molecules in different initial configurations offers a unique perspective that could be complementary to mainstream methods-not just in the case of C2H2 but other chemical systems as well. We also describe some improvements to the 3D momentum imaging methods that facilitate the study of molecular dynamics. One of these developments is a method to distinguish and evaluate the momenta of neutral-neutral channels resulting from the fragmentation of negative ion beams. The second is a technique for imaging the breakup of long-lived metastable molecules decaying in flight to the detector and retrieving the lifetime(s) of the populated states. Our collaborative efforts in adaptive closed-loop control are also discussed. Here, an evolutionary learning algorithm supplied with experimental feedback obtains optimally-shaped ultrashort laser pulses for driving targeted molecular dynamics. While the complexity of the shaped pulses can make interpretation challenging, the combination of these efforts with basic experiments like those we perform using ion beams can help. In closing, the work presented in this thesis extends from diatomic to polyatomic molecules, following the natural progression of building from simpler to more complex systems. We believe that the results of these efforts aid in the advancement of understanding strong-field molecular dynamics and will stimulate future research endeavors along these directions.
Download or read book Ultrafast Dynamics of Polyatomic Molecules Under Intense Laser Radiation written by Vahan Artsruni Senekerimyan and published by . This book was released on 2004 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress in Ultrafast Intense Laser Science III written by See Leang Chin and published by Springer Science & Business Media. This book was released on 2008-01-23 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: The PUILS series presents Progress in Ultrafast Intense Laser Science. This third volume in the series covers a diverse range of disciplines, focusing on such topics as strong field ionization of atoms, ionization and fragmentation of molecules and clusters, generation of high-order harmonics and attosecond pulses, filamentation and laser plasma interaction, and the development of ultrashort and ultrahigh-intensity light sources.
Download or read book Ultrafast Phenomena XIV written by Takayoshi Kobayashi and published by Springer Science & Business Media. This book was released on 2005 with total page 954 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrafast Phenomena XIV presents the latest advances in ultrafast science, including ultrafast laser and measurement technology as well as studies of ultrafast phenomena. Pico-, femto-, and atosecond processes relevant in physics, chemistry, biology and engineering are presented. Ultrafast technology is now having a profound impact within a wide range of applications, among them imaging, material diagnostics, and transformation and high-speed optoelectronics. This book summarizes results presented at the 14th Ultrafast Phenomena Conference and reviews the state of the art in this important and rapidly advancing field.
Download or read book Tutorials in Molecular Reaction Dynamics written by Mark Brouard and published by Royal Society of Chemistry. This book was released on 2015-11-09 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this excellent textbook is the topic of molecular reaction dynamics. The chapters are all written by internationally recognised researchers and, from the outset, the contributors are writing with the young scientist in mind. The easy to use, stand-alone, chapters make it of value to students, teachers, and researchers alike. Subjects covered range from the more traditional topics, such as potential energy surfaces, to more advanced and rapidly developing areas, such as femtochemistry and coherent control. The coverage of reaction dynamics is very broad, so many students studying chemical physics will find elements of this text interesting and useful. Tutorials in Molecular Reaction Dynamics includes extensive references to more advanced texts and research papers, and a series of 'Study Boxes' help readers grapple with the more difficult concepts. Each chapter is thoroughly cross-referenced, helping the reader to link concepts from different branches of the subject. Worked problems are included, and each chapter concludes with a selection of problems designed to test understanding of the subjects covered. Supplementary reading material, and worked solutions to the problems, are contained on a secure website.
Download or read book Analysis and Control of Ultrafast Photoinduced Reactions written by Oliver Kuhn and published by Springer. This book was released on 2016-05-01 with total page 860 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamical processes in molecules like bond shaking, breaking or making c- monlytakeplaceonatimescalefromthepico-downtothefemtosecondrange. Theadventofequallyfastlasersourcesandreal-timeobservationschemeslike pump-probe spectroscopy has facilitated the direct insight into such processes wheninitiatedbylight. Inparallelthedevelopmentofadvancedcomputational methods treating the dynamics of photoexcited molecular systems allowed a convergence between theoretical description and experimental observation of such ultrafast dynamical processes. Consequently, the idea emerged, not only to analyze, but also to control molecular dynamics in real time by adequately designed light ?elds. Stimulated by theoretical concepts for in'uencing the motion of molecular wave packets by means of simple few-parameter elect- magnetic ?eld sequences, experiments were driven toward a practical reali- tion of arbitrarily shaped laser pulses. This development culminated in the active feedback control of even complex systems. In addition this o'ers the unique possibility not only to determine the outcome of chemical reactions, butalsotoretrievespeci'cinformationaboutthechosendynamicalpathways, that is, to perform analysis by control. This book illustrates a vital research ?eld by covering a broad spectrum of molecular systems with growing complexity while demonstrating at the same time the convergence of experimental and theoretical approaches. After a g- eral introduction in Chapter 1, Chapter 2 starts with small isolated molecules in the unperturbed environment of the gas phase and Chapter 3 proceeds to more complex systems, but still in vacuum. A higher level of complexity is then reached in Chapter 4 where small molecules in a rare gas matrices are discussed serving as prototype examples for condensed phase dynamics.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 906 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Femtochemistry Ultrafast Chemical And Physical Processes In Molecular Systems written by Majed Chergui and published by World Scientific. This book was released on 1996-04-30 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the latest experimental and theoretical developments in the field of femtochemistry, with papers describing the physics and chemistry of ultrafast processes in small molecules, complex molecular systems, clusters, biological systems, solids, matrices, liquids and at surfaces and interfaces. The recent developments in frequency-domain studies of femtodynamics are also presented. In addition, the latest achievements in femtosecond control of chemical reactions are presented, together with the newest techniques in real-time probing of reactions such as ultrafast x-ray or electron diffraction. The papers are rich in references giving a clearcut state-of-the-art of the topics being discussed. The book should be a valuable tool to all persons in the field and to young scientists.Contributors include: A H Zewail, J Jortner, V S Letokhov, J Manz, R S Berry, C Wittig, K B Eisenthal, A W Castleman Jr., J T Hynes, W H Gadzuk, R Kosloff, S Mukamel, K R Wilson; G Fleming, D Wiersma, K Yoshihara, V Sundström, A Apkarian, N Scherer, A Myers, R Schinke, J R Huber, R B Gerber, G Gerber and P M Champion.
Download or read book Attosecond Molecular Dynamics written by Marc J J Vrakking and published by Royal Society of Chemistry. This book was released on 2018-08-31 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Attosecond science is a new and rapidly developing research area in which molecular dynamics are studied at the timescale of a few attoseconds. Within the past decade, attosecond pump–probe spectroscopy has emerged as a powerful experimental technique that permits electron dynamics to be followed on their natural timescales. With the development of this technology, physical chemists have been able to observe and control molecular dynamics on attosecond timescales. From these observations it has been suggested that attosecond to few-femtosecond timescale charge migration may induce what has been called “post-Born-Oppenheimer dynamics”, where the nuclei respond to rapidly time-dependent force fields resulting from transient localization of the electrons. These real-time observations have spurred exciting new advances in the theoretical work to both explain and predict these novel dynamics. This book presents an overview of current theoretical work relevant to attosecond science written by theoreticians who are presently at the forefront of its development. It is a valuable reference work for anyone working in the field of attosecond science as well as those studying the subject.
