Download or read book Generation of Attosecond X ray Pulses Beyond the Atomic Unit of Time Using Laser Induced Microbunching in Electron Beams written by and published by . This book was released on 2009 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ever since the discovery of mode-locking, efforts have been devoted to reducing the duration of laser pulses since the ultrashort pulses are critical to explore the dynamics occurred on a ever-shorter timescale. In this paper we describe a scheme that's capable of generating intense attosecond x-ray pulses with duration beyond the atomic unit of time ((almost equal to)24 attoseconds). The scheme combines the echo-enabled harmonic generation technique with the bunch compression which allows one to generate harmonic numbers of a few hundred in a microbunched beam through up-conversion of the frequency of a UV seed laser. A few-cycle intense IR laser is used to generate the required energy chirp in the beam for bunch compression and for selection of an attosecond x-ray pulse. Using a representative realistic set of parameters, we show that 1 nm x-ray pulse with peak power of a few hundred MW and duration as short as 20 attoseconds (FWHM) can be generated from a 200 nm UV seed laser. The proposed scheme may enable the study of electronic dynamics with a resolution beyond the atomic unit of time and may open a new regime of ultrafast sciences.
Download or read book Proceedings of the 8th International Conference on Attosecond Science and Technology written by Argenti and published by Springer Nature. This book was released on 2024 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access volume brings together selected papers from the 8th International Conference on Attosecond Science and Technology. The contributions within represent the latest advances in attosecond science, covering recent progress in ultrafast electron dynamics in atoms, molecules, clusters, surfaces, solids, nanostructures and plasmas, as well as the generation of sub-femtosecond XUV and X-ray pulses, either through table-top laser setups or with X-ray free-electron lasers. In addition to highlighting key advances and outlining the state of the field, the conference and its proceedings serve to introduce junior researchers to the community, promote collaborations, and represent the global and topical diversity of the field.
Download or read book Methods of Attosecond X Ray Pulse Generation written by and published by . This book was released on 2005 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: We review several proposals for generation of solitary attosecond pulses using two types of free electron lasers which are envisioned as future light sources for studies of ultra-fast dynamics using soft and hard x-rays.
Download or read book From Femto to Attoscience and Beyond written by Janina Marciak-Kozłowska and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fascinating developments in optical pulse engineering over the last 20 years lead to the generation of laser pulses as short as few femtosecond, providing a unique tool for high resolution time domain spectroscopy. However, a number of the processes in nature evolve with characteristic times of the order of 1 fs or even shorter. Time domain studies of such processes require at first place sub-fs resolution, offered by pulse depicting attosecond localisation. The generation, characterisation and proof of principle applications of such pulses is the target of the attoscience. In this book the interaction of the attosecond laser pulses with matter is investigated. The Proca's termal equation for laster - matter interaction is formulated and solved. It is shown that for attosecond laster pulses the Proca's thermal equation can be simplified and thermal Klein-Gordon equation is obtained. The book is divided into six chapters and the Epilogue presents the contemporary status of the attoscience: sub-femtosecond laster-matter interactions, master equations: Proca and Klein-Gordon equations and the perspectives: Attosecond Free Electron Laser (AFEL), LASETRON and Entangled Photon Laser (EPL).
Download or read book Generation and Application of Attosecond Pulses written by Zsolt Diveki and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: To capture electronic rearrangements inside a molecule or during chemical reactions, attosecond (as, 1 as =10-18 s) time resolution is needed. To create a light pulse with this duration, the central frequency has to be in the XUV range and cover several tens of eVs. Moreover, the frequency components have to be synchronized. The so called High Harmonic Generation (HHG) in gases well suits this task. During this process a high intensity laser pulse is focused in a gas jet, where its electric field bends the potential barrier of an atom allowing an electron wave packet (EWP) to tunnel ionize. Following the electric field of the laser the EWP gets accelerated, gaining a large kinetic energy that may be released as a high energy (XUV) photon in the event of a re-collision with the ionic core. These recolliding EWP probe the structure and dynamics of the core in a self-probing scheme: the EWP, that is emitted by the molecule at a certain time, probes itself later. More precisely, this ”self-probing” scheme gives access to the complex valued recombination dipole moment (RDM) of the molecule which is determined by both the nuclear and electronic structure. The recombination encodes these characteristics into the spectral amplitude, phase and polarization state of the harmonic radiation emitted by the dipole. Due to the coherent nature of HHG it is possible to measure all these three parameters. Moreover, it is in principle possible through a tomographic procedure to reconstruct the radiating orbital.The objective of my thesis was two-fold. By implementing advanced characterization techniques of the harmonic amplitude, phase and polarization we studied i) the electronic structure of N2 and laser induced multi-channel tunnel ionization. We presented the reconstruction of molecular orbitals and revealed the ionization channel dependent ultrafast nuclear vibration. We also studied ii) the reflectivity and dispersion of recently designed chirped XUV mirrors that can shape the temporal profile of attosecond pulses. With these mirrors we could control the spectral phase over 20 eV and compensate the GDD of the harmonics or introduce a TOD. We also proposed a novel attosecond pulse shaper.
Download or read book Enhancement Cavities for the Generation of Extreme Ultraviolet and Hard X Ray Radiation written by Henning Carstens and published by Springer. This book was released on 2018-06-22 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis discusses the power scaling of ultrashort pulses in enhancement cavities, utilized in particular for frequency conversion processes, such as Thomson scattering and high-harmonic generation. Using custom optics for ultrashort-pulse enhancement cavities, it demonstrates for the first time that at the envisaged power levels, the mitigation of thermal effects becomes indispensable even in cavities comprising solely reflective optics. It also studies cavities with large beams, albeit with low misalignment sensitivity, as a way to circumvent intensity-induced mirror damage. Average powers of several hundred kilowatts are demonstrated, which benefit hard x-ray sources based on Thomson scattering. Furthermore, pulses as short as 30 fs were obtained at more than 10 kW of average power and employed for high-harmonic generation with photon energies exceeding 100 eV at 250 MHz repetition rate, paving the way for frequency comb spectroscopy in this spectral region.
Download or read book Connecting Lab Based Attosecond Science with FEL Research written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last few years laboratory-scale femtosecond laser-based research using XUV light has developed dramatically following the successful development of attosecond laser pulses by means of high-harmonic generation. Using attosecond laser pulses, studies of electron dynamics on the natural timescale that electronic processes occur in atoms, molecules and solids can be contemplated, providing unprecedented insight into the fundamental role that electrons play in photo-induced processes. In my talk I will briefly review the present status of the attosecond science research field in terms of present and foreseen capabilities, and discuss a few recent applications, including a first example of the use of attosecond laser pulses in molecular science. In addition, I will discuss very recent results of experiments where photoionization of dynamically aligned molecules is investigated using a high-harmonics XUV source. Photoionization of aligned molecules becomes all the more interesting if the experiment is performed using x-ray photons. Following the absorption of x-rays, ejected photoelectrons can be used as a probe of the (time-evolving) molecular structure, making use of intra-molecular electron diffraction. This amounts, as some have stated, to "illuminating the molecule from within". I will present the present status of our experiments on this topic making use of the FLASH free electron laser in Hamburg. Future progress in this research field not only depends on the availability of better and more powerful light sources, but also requires sophisticated detector strategies. In my talk I will explain how we are trying to meet some of the experimental challenges by using the Medipix family of detectors, which we have already used for time- and space-resolved imaging of electrons and ions.
Download or read book Generation and Characterization of Isolated Attosecond Pulse in the Soft X ray Regime written by Jie Li and published by . This book was released on 2018 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observation of any atomic and molecular dynamics requires a probe that has a timescale comparable to the dynamics itself. Ever since the invention of laser, the temporal duration of the laser pulse has been incrementally reduced from several nanoseconds to just attoseconds. Picosecond and femtosecond laser pulses have been widely used to study molecular rotation and vibration.
Download or read book Femtosecond Laser Pulses written by Claude Rulliere and published by Springer Science & Business Media. This book was released on 2005 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Study on Generation of Attosecond Pulse with Polarization Gating written by Shambhu Ghimire and published by . This book was released on 2007 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Finally, in order to temporarily characterize the attosecond pulses we designed and built an "Attosecond Streak Camera". Most of such cameras to date are limited to measuring a 1 dimensional energy spectrum and have only a few degrees of acceptance angle. Our camera is capable of measuring 2d momentum of the photoelectrons with large acceptance angle, for example ∼65° at the photoelectron of energy ∼15 eV. Recently, we observed the sidebands in addition to the main peaks in their laser assisted XUV photoelectron spectrum. The single attosecond pulses, after being characterized with this high speed camera, can be used to explore the dynamics of electrons at the attosecond scale.
Download or read book Ultrafast Phenomena XV written by Paul Corkum and published by Springer Science & Business Media. This book was released on 2007-07-10 with total page 853 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is a collection of papers presented at the Fifteenth International Conference on Ultrafast Phenomena held at the Asilomar Conference Grounds, Pacifc Grove, CA, USA, from July 31 – August 4, 2006. The Ultrafast P- nomena conferences are held every two years and provide a forum for disc- sion of the latest results in ultrafast optics and their applications in science and engineering. These meetings bring together researchers spanning several felds of science and engineering to discuss and debate the latest advances in ult- fast science. This unique forum provides a conduit for the greater dissemi- tion of the latest advances using ultrashort coherent pulses of light. More than 280 papers were presented. Signifcant progress in creating ever shorter pulses of light was reported in the attosecond range, with new applications in high harmonic generation and frequency comb metrology. Multidimensional sp- troscopy is rapidly evolving to provide new insights into quantum coherence and interactions in complex systems. Improvements in time resolved electron and x-ray diffraction provide better atomic scale perspectives on structural dynamics. These examples are but a small subset of the collected works ga- ered in this volume, which provides a valuable synopsis of the recent advances and impact of ultrafast technology in illuminating fundamental processes in physics, chemistry, and biology. There were 323 attendees at the meeting, more than one third of which were graduate and postdoctoral students. Increased s- dent attendance energized the proceedings.
Download or read book Towards Intense Single Attosecond Pulse Generation from a 400 NM Driving Laser written by Yan Cheng and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Attosecond pulse generation is a powerful tool to study electron dynamics in atoms and molecules. However, application of attosecond pulses is limited by the low photon flux of attosecond sources. Theoretical models predict that the harmonic efficiency scales as [lambda][superscript]-6 in the plateau region of the HHG spectrum, where [lambda] is the wavelength of the driving laser. This indicates the possibility of generating more intense attosecond pulses using short wavelength driving lasers. The purpose of this work is to find a method to generate intense single attosecond pulses using a 400 nm driving laser. In our experiments, 400 nm femtosecond laser pulses are used to generate high harmonics. First, the dependence of the high harmonic generation yield on the ellipticity of 400 nm driving laser pulse is studied experimentally, and it is compared with that of 800 nm driving lasers. A semi-classical theory is developed to explain the ellipticity dependence where the theoretical calculations match experiment results very well. Next, 400 nm short pulses (sub-10 fs) are produced with a hollow core fiber and chirped mirrors. Finally, we propose a scheme to extract single attosecond pulses with the Generalized Double Optical Gating (GDOG) method.
Download or read book Generation and Characterization of Sub 70 Isolated Attosecond Pulses written by Qi Zhang and published by . This book was released on 2014 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics occurring on microscopic scales, such as electronic motion inside atoms and molecules, are governed by quantum mechanics. However, the Schrödinger equation is usually too complicated to solve analytically for systems other than the hydrogen atom. Even for some simple atoms such as helium, it still takes months to do a full numerical analysis. Therefore, practical problems are often solved only after simplification. The results are then compared with the experimental outcome in both the spectral and temporal domain. For accurate experimental comparison, temporal resolution on the attosecond scale is required. This had not been achieved until the first demonstration of the single attosecond pulse in 2001. After this breakthrough, "attophysics" immediately became a hot field in the physics and optics community. While the attosecond pulse has served as an irreplaceable tool in many fundamental research studies of ultrafast dynamics, the pulse generation process itself is an interesting topic in the ultrafast field. When an intense femtosecond laser is tightly focused on a gaseous target, electrons inside the neutral atoms are ripped away through tunneling ionization. Under certain circumstances, the electrons are able to reunite with the parent ions and release photon bursts lasting only tens to hundreds of attoseconds. This process repeats itself every half cycle of the driving pulse, generating a train of single attosecond pulses which lasts longer than one femtosecond. To achieve true temporal resolution on the attosecond time scale, single isolated attosecond pulses are required, meaning only one attosecond pulse can be produced per driving pulse.
Download or read book Generation of Attosecond Light Pulses from Gas and Solid State Media written by Stefanos Chatziathanasiou and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Towards the Generation of Isolated Attosecond Pulses in the Water Window written by Seth Lucien Cousin and published by . This book was released on 2017 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Attosecond science investigates the realm of processes that happen in fleetingly short passages of time. One attosecond to one second, is what one second is to the age of the universe! Advances in lasers and specifically ultra-short pulsed lasers have opened the door to this extreme frontier of physics. In this thesis I will describe what is required from a laser system in order to access these time scales. The stringent requirements needed motivated us to extensively study, model, redesign and then finally rebuild our laser system making it capable of delivering the necessary laser pulses. Characterisation of these types of laser pulses is essential in making them usable in the pursuit of a fundamental understanding of ultrashort physical processes. Two new characterisation techniques have been developed to add to the suite of tools available to the scientific community to achieve the complicated goal of characterising femtosecond laser pulses. To jump from the femtosecond regime to the attosecond regime, high harmonic generation is currently the defacto method of getting there. I will give a detailed description of our high harmonic beamline, which ultimately is used to perform the first water-window radiation range spectroscopy from a high harmonic source. Intrinsic to the radiation generated for spectroscopy is the sub-femtosecond temporal structure of the radiation. Temporal characterisation of attosecond pulses is traditionally done using the attosecond streaking technique however until now, this technique has not been used in the water-window. X-ray pulses possessing our ultra-broad bandwidth and central photon energy are unprecedented, making this the first time that a streaking experiment is done in this regime.
Download or read book Atoms Solids and Plasmas in Super Intense Laser Fields written by Dimitri Batani and published by Springer Science & Business Media. This book was released on 2001-09-30 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 30th Course of the International School of Quantum Electronics on Atoms, Solids and Plasmas in Super-Intense Laser Fields, held 8-14 July, in Erice, Sicily
Download or read book Synchrotron Light Sources and Free Electron Lasers written by Eberhard J. Jaeschke and published by Springer. This book was released on 2016-05-27 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hardly any other discovery of the nineteenth century did have such an impact on science and technology as Wilhelm Conrad Röntgen’s seminal find of the X-rays. X-ray tubes soon made their way as excellent instruments for numerous applications in medicine, biology, materials science and testing, chemistry and public security. Developing new radiation sources with higher brilliance and much extended spectral range resulted in stunning developments like the electron synchrotron and electron storage ring and the freeelectron laser. This handbook highlights these developments in fifty chapters. The reader is given not only an inside view of exciting science areas but also of design concepts for the most advanced light sources. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of Terahertz radiation sources and upcoming brilliant light sources driven by laser-plasma accelerators. The applications of the most advanced light sources and the advent of nanobeams and fully coherent x-rays allow experiments from which scientists in the past could not even dream. Examples are the diffraction with nanometer resolution, imaging with a full 3D reconstruction of the object from a diffraction pattern, measuring the disorder in liquids with high spatial and temporal resolution. The 20th century was dedicated to the development and improvement of synchrotron light sources with an ever ongoing increase of brilliance. With ultrahigh brilliance sources, the 21st century will be the century of x-ray lasers and their applications. Thus, we are already close to the dream of condensed matter and biophysics: imaging single (macro)molecules and measuring their dynamics on the femtosecond timescale to produce movies with atomic resolution.
