Attosecond and XUV Physics: Ultrafast Dynamics and Spectroscopy

Description

This book provides fundamental knowledge in the fields of attosecond science and free electron lasers, based on the insight that the further development of both disciplines can greatly benefit from mutual exposure and interaction between the two communities. With respect to the interaction of high intensity lasers with matter, it covers ultrafast lasers, high-harmonic generation, attosecond pulse generation and characterization. Other chapters review strong-field physics, free electron lasers and experimental instrumentation. Written in an easy accessible style, the book is aimed at graduate and postgraduate students so as to support the scientific training of early stage researchers in this emerging field. Special emphasis is placed on the practical approach of building experiments, allowing young researchers to develop a wide range of scientific skills in order to accelerate the development of spectroscopic techniques and their implementation in scientific experiments. The editors are managers of a research network devoted to the education of young scientists, and this book idea is based on a summer school organized by the ATTOFEL network. Contents List of Contributors XIII 1 1.1 1.2 1.2.1 1.2.2 1.2.3 1.2.4 1.3 1.4 1.5 1.6 Attosecond and XUV Physics: Ultrafast Dynamics and Spectroscopy 1 Marc Vrakking Introduction 1 The Emergence of Attosecond Science 2 Attosecond Pulse Trains and Isolated Attosecond Pulses 3 Characterization of Attosecond Laser Pulses 4 Experimental Challenges in Attosecond Science 5 Attosecond Science as a Driver for Technological Developments 6 Applications of Attosecond Laser Pulses 7 Ultrafast Science Using XUV/X-ray Free Electron Lasers 9 The Interplay between Experiment and Theory 11 Conclusion and Outlook 12 References 13 Part One Laser Techniques 17 2 2.1 2.2 2.3 2.4 3 3.1 3.1.1 3.2 3.2.1 3.2.2 3.2.3 3.2.4 Ultrafast Laser Oscillators and Amplifiers 19 Uwe Morgner Introduction 19 Mode-Locking and Few-Cycle Pulse Generation High-Energy Oscillators 23 Laser Amplifiers 25 References 29 20 Ultrashort Pulse Characterization 37 Adam S. Wyatt Motivation: Why Ultrafast Metrology? 37 Ultrafast Science: High-Speed Photography in the Extreme Formal Description of Ultrashort Pulses 42 Sampling Theorem 45 Chronocyclic Representation of Ultrafast Pulses 46 Space-Time Coupling 46 Accuracy, Precision and Consistency 49 38VI Contents 3.3 3.4 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5 3.5 3.5.1 3.5.2 3.6 4 4.1 4.2 4.2.1 4.2.2 4.3 4.3.1 4.3.2 4.3.3 4.3.4 4.3.5 4.4 4.4.1 4.4.2 4.4.3 4.5 4.5.1 4.5.2 4.5.3 4.5.4 4.5.5 4.6 5 5.1 5.2 5.2.1 5.2.2 Linear Filter Analysis 51 Ultrafast Metrology in the Visible to Infrared 53 Temporal Correlations 53 Spectrography 55 Sonography 60 Tomography 60 Interferometry 63 Ultrafast Metrology in the Extreme Ultraviolet 73 Complete Characterization of Ultrashort XUV Pulses via Photoionization Spectroscopy 75 XUV Interferometry 81 Summary 85 References 85 Carrier Envelope Phase Stabilization 95 Vincent Crozatier Introduction 95 CEP Fundamentals 96 Time Domain Representation 96 Frequency Domain Representation 97 Stabilization Loop Fundamentals 99 The Noisy Source 99 Noise Detection 100 Open-Loop Noise Analysis 101 Feedback 102 Closed-Loop Noise Analysis 103 CEP in Oscillators 104 Oscillators Peculiarities 105 CEP Detection 107 Actuation 110 CEP in Amplifiers 115 Amplifier Peculiarities 116 CEP Detection 119 Actuation 123 Feedback Results 124 Parametric Amplification 126 Conclusion 129 References 129 Towards Tabletop X-Ray Lasers 135 Philippe Zeitoun, Eduardo Oliva, Thi Thu Thuy Le, Stéphane Sebban, Marta Fajardo, David Ros, and Pedro Velarde Context and Objectives 135 Choice of Plasma-Based Soft X-Ray Amplifier 137 Basic Aspects of High Harmonic Amplification 138 Basic Aspects of Plasma Amplifiers 140Contents 5.3 5.3.1 5.3.2 5.4 5.5 5.6 2D Fluid Modeling and 3D Ray Trace 141 ARWEN Code 142 Model to Obtain 2D Maps of Atomic Data 143 The Bloch–Maxwell Treatment 149 Stretched Seed Amplification 157 Conclusion 170 References 171 Part Two Theoretical Methods 177 6 6.1 6.2 6.3 6.3.1 6.3.2 6.4 6.4.1 6.4.2 6.5 6.5.1 6.6 6.7 7 7.1 7.2 7.3 7.4 7.5 7.6 7.6.1 7.6.2 7.7 7.8 7.9 7.10 7.11 7.11.1 7.11.2 7.12 Ionization in Strong Low-Frequency Fields 179 Misha Ivanov Preliminaries 179 Speculative Thoughts 179 Basic Formalism 181 Hamiltonians and Gauges 181 Formal Solutions 182 The Strong-Field Approximation 184 The Volkov Propagator and the Classical Connection 185 Transition Amplitudes in the SFA 186 Strong-Field Ionization: Exponential vs. Power Law 189 The Saddle Point Approximation and the Classical Connection 190 Semiclassical Picture of High Harmonic Generation 195 Conclusion 198 References 199 Multielectron High Harmonic Generation: Simple Man on a Complex Plane 201 Olga Smirnova and Misha Ivanov Introduction 201 The Simple Man Model of High Harmonic Generation (HHG) 203 Formal Approach for One-Electron Systems 205 The Lewenstein Model: Saddle Point Equations for HHG 209 Analysis of the Complex Trajectories 214 Factorization of the HHG Dipole: Simple Man on a Complex Plane 221 Factorization of the HHG Dipole in the Frequency Domain 222 Factorization of the HHG Dipole in the Time Domain 224 The Photoelectron Model of HHG: The Improved Simple Man 227 The Multichannel Model of HHG: Tackling Multielectron Systems 231 Outlook 238 Appendix A: Supplementary Derivations 241 Appendix B: The Saddle Point Method 242 Integrals on the Real Axis 243 Stationary Phase Method 248 Appendix C: Treating the Cutoff Region: Regularization of Divergent Stationary Phase Solutions 250 VIIVIII Contents 251 7.13 Appendix D: Finding Saddle Points for the Lewenstein Model References 253 8 Time-Dependent Schrödinger Equation 257 Armin Scrinzi Atoms and Molecules in Laser Fields 258 Solving the TDSE 259 Discretization of the TDSE 260 Finite Elements 263 Scaling with Laser Parameters 265 Time Propagation 266 Runge–Kutta Methods 267 Krylov Subspace Methods 268 Split-Step Methods 269 Absorption of Outgoing Flux 269 Absorption for a One-Dimensional TDSE 270 Observables 272 Ionization and Excitation 272 Harmonic Response 274 Photoelectron Spectra 275 Two-Electron Systems 278 Very Large-Scale Grid-Based Approaches 278 Basis and Pseudospectral Approaches 278 Few-Electron Systems 282 MCTDHF: Multiconfiguration Time-Dependent Hartree–Fock 283 Dynamical Multielectron Effects in High Harmonic Generation 285 Nuclear Motion 287 References 290 8.1 8.2 8.2.1 8.2.2 8.2.3 8.3 8.3.1 8.3.2 8.3.3 8.4 8.4.1 8.5 8.5.1 8.5.2 8.5.3 8.6 8.6.1 8.6.2 8.7 8.7.1 8.7.2 8.8 9 9.1 9.2 9.3 9.4 9.4.1 9.4.2 9.4.3 9.4.4 9.4.5 9.5 9.6 9.7 Angular Distributions in Molecular Photoionization 293 Robert R. Lucchese and Danielle Dowek Introduction 293 One-Photon Photoionization in the Molecular Frame 297 Methods for Computing Cross-Sections 302 Post-orientation MFPADs 304 MFPADs for Linear Molecules in the Axial Recoil Approximation 304 MFPADs for Nonlinear Molecules in the Axial Recoil Approximation 306 Breakdown of the Axial Recoil Approximation Due to Rotation 308 Breakdown of the Axial Recoil Approximation Due to Vibrational Motion 309 Electron Frame Photoelectron Angular Distributions 309 MFPADs from Concurrent Orientation in Multiphoton Ionization 310 Pre-orientation or Alignment, Impulsive Alignment 314 Conclusions 315 References 315Contents Part Three High Harmonic Generation and Attosecond Pulses 10 10.1 10.2 10.3 10.4 10.5 11 11.1 11.1.1 11.1.2 11.1.3 11.1.4 11.1.5 11.2 11.2.1 11.2.2 11.2.3 11.3 11.4 11.4.1 11.4.2 11.4.3 11.4.4 11.5 12 12.1 12.2 12.3 12.3.1 12.3.2 12.3.3 12.4 12.4.1 12.4.2 12.4.3 321 High-Order Harmonic Generation and Attosecond Light Pulses: An Introduction 323 Anne L’Huillier Early Work, 1987–1993 323 Three-Step Model, 1993–1994 325 Trajectories and Phase Matching, 1995–2000 328 Attosecond Pulses 2001 331 Conclusion 332 References 335 Strong-Field Interactions at Long Wavelengths 339 Manuel Kremer, Cosmin I. Blaga, Anthony D. DiChiara, Stephen B. Schoun, Pierre Agostini, and Louis F. DiMauro Theoretical Background 340 Keldysh Picture of Ionization in Strong Fields 340 Classical Perspectives on Postionization Dynamics 341 High-Harmonic Generation 342 Wavelength Scaling of High-Harmonic Cutoff and Attochirp 342 In-situ and RABBITT Technique 344 Mid-IR Sources and Beamlines at OSU 346 2-μm Source 346 3.6-μm Source 347 OSU Attosecond Beamline 347 Strong-Field Ionization: The Single-Atom Response 348 High-Harmonic Generation 350 Harmonic Cutoff and Harmonic Yield 350 Attochirp 352 In-situ Phase Measurement 352 RABBITT Method 355 Conclusions and Future Perspectives 356 References 356 Attosecond Dynamics in Atoms 361 Giuseppe Sansone, Francesca Calegari, Matteo Lucchini, and Mauro Nisoli Introduction 361 Single-Electron Atom: Hydrogen 362 Two-Electron Atom: Helium 365 Electronic Wave Packets 366 Autoionization: Fano Profile 371 Two-Photon Double Ionization 373 Multielectron Systems 380 Neon: Dynamics of Shake-Up States 381 Neon: Delay in Photoemission 384 Argon: Fano Resonance 386 IXX Contents 12.4.4 12.4.5 12.4.6 Krypton: Auger Decay 388 Krypton: Charge Oscillation 390 Xenon: Cascaded Auger Decay 391 References 393 13 Application of Attosecond Pulses to Molecules 395 Franck Lépine Attosecond Dynamics in Molecules 395 State-of-the-Art Experiments Using Attosecond Pulses 397 Ion Spectroscopy 398 Electron Spectroscopy 402 Photo Absorption 404 Theoretical Work 405 Electron Dynamics in Small Molecules 405 Electron Dynamics in Large Molecules 406 Perspectives 413 Molecular Alignment and Orientation 413 Electron Delocalization between DNA Group Junction 414 Similar Dynamics in Water and Ice 416 More 416 Conclusion 416 References 417 13.1 13.2 13.2.1 13.2.2 13.2.3 13.3 13.3.1 13.3.2 13.4 13.4.1 13.4.2 13.4.3 13.4.4 13.5 14 14.1 14.2 14.2.1 14.2.2 14.3 14.3.1 14.3.2 14.3.3 14.4 14.4.1 14.4.2 14.4.3 14.4.4 14.4.5 14.5 Attosecond Nanophysics 421 Frederik Süßmann, Sarah L. Stebbings, Sergey Zherebtsov, Soo Hoon Chew, Mark I. Stockman, Eckart Rühl, Ulf Kleineberg, Thomas Fennel, and Matthias F. Kling Introduction 421 Attosecond Light-Field Control of Electron Emission and Acceleration from Nanoparticles 425 Imaging of the Electron Emission from Isolated Nanoparticles 426 Microscopic Analysis of the Electron Emission 429 Few-Cycle Pump-Probe Analysis of Cluster Plasmons 433 Basics of Spectral Interferometry 433 Oscillator Model Results for Excitation with Gaussian Pulses 435 Spectral Interferometry Analysis of Plasmons in Small Sodium Clusters 437 Measurements of Plasmonic Fields with Attosecond Time Resolution 439 Attosecond Nanoplasmonic Streaking 439 The Regimes of APS Spectroscopy 441 APS Spectroscopy of Collective Electron Dynamics in Isolated Nanoparticles 442 Attosecond Nanoscope 444 Experimental Implementation of the Attosecond Nanoscope 446 Nanoplasmonic Field-Enhanced XUV Generation 449Contents 14.5.1 14.5.2 14.6 Tailoring of Nanoplasmonic Field Enhancement for HHG 450 Generation of Single Attosecond XUV Pulses in Nano-HHG 452 Conclusions and Outlook 454 References 455 Part Four Ultra Intense X-Ray Free Electron Laser Experiments 463 15 15.1 15.2 15.2.1 15.2.2 15.2.3 15.3 15.3.1 15.3.2 15.3.3 15.3.4 15.4 15.4.1 15.4.2 15.4.3 15.5 15.5.1 15.5.2 15.6 16 16.1 16.1.1 16.1.2 16.2 16.2.1 16.2.2 16.3 16.4 16.5 17 17.1 17.2 Strong-Field Interactions at EUV and X-Ray Wavelengths 465 Artem Rudenko Introduction 465 Experimental Background 467 What Is a “Strong” Field? 467 Basic Parameters of Intense High-Frequency Radiation Sources 469 Detection Systems 471 Atoms and Molecules under Intense EUV Light 473 Two-Photon Single Ionization of Helium 473 Few-Photon Double Ionization of Helium and Neon 476 Multiple Ionization of Atoms 485 EUV-Induced Fragmentation of Simple Molecules 487 EUV Pump–EUV Probe Experiments 493 Split-and-Delay Arrangements and Characterization of the EUV Pulses 493 Nuclear Wave Packet Imaging in Diatomic Molecules 495 Isomerization Dynamics of Acetylene Cations 498 Experiments in the X-Ray Domain 499 Multiple Ionization of Heavy Atoms: Role of Resonant Excitations 500 Multiphoton Ionization of Molecules Containing High-Z Atoms 506 Summary and Outlook 510 References 512 Ultraintense X-Ray Interactions at the Linac Coherent Light Source 529 Linda Young Introduction 529 Comparison of Ultrafast, Ultraintense Optical, and X-Ray Lasers 531 X-Ray Atom Interactions 533 Atomic and Molecular Response to Ultraintense X-Ray Pulses 536 Nonresonant High-Intensity X-Ray Phenomena 537 Resonant High-Intensity X-Ray Phenomena 540 Ultrafast X-Ray Probes of Dynamics 543 Characterization of LCLS Pulses 544 Outlook 546 References 549 Coherent Diffractive Imaging 557 Willem Boutu, Betrand Carré, and Hamed Merdji Introduction 557 Far-Field Diffraction 559 XIXII Contents 17.2.1 17.2.2 17.2.3 17.2.4 17.3 17.3.1 17.3.2 17.3.3 17.3.4 17.4 17.4.1 17.4.2 17.4.3 17.5 17.5.1 17.5.2 17.6 Optical Point of View 559 Born Approximation 561 Resolution 562 Comments on the Approximations 564 Source Requirements 565 Coherence 565 Signal-to-Noise Ratio 568 Dose 569 Different XUV Sources Comparison 572 Solving the Phase Problem 572 Oversampling Method 572 Basics on Iterative Phasing Algorithms 574 Implementations of Phase Retrieval Algorithms 577 Holography 583 Fourier Transform Holography 583 HERALDO 587 Conclusions 590 References 592 Index 599