Resonance Enhancement in Laser-Produced Plasmas

Rashid A. Ganeev is a Professor at Changchun Institute of Optics, Fine Mechanics and Physics in China. His main area of research is a nonlinear optics, including high-order harmonic generation of laser radiation in plasmas and investigation of the nonlinear optical properties of various media. He is also interested in the investigation and construction of coherent extreme ultraviolet radiation sources and high-power solid-state laser physics.

Preface xiii

1 High-Order Harmonic Studies of the Role of Resonances on the Temporal and Efficiency Characteristics of Converted Coherent Pulses: Different Approaches 1

1.1 Resonance Harmonic Generation in Gases:Theory and Experiment 1

1.2 Role of Resonances in Plasma Harmonic Experiments: Intensity and Temporal Characterization of Harmonics 9

References 13

2 Different Theoretical Approaches in Plasma HHG Studies at Resonance Conditions 17

2.1 Comparative Analysis of the High-Order Harmonic Generation in the Laser Ablation Plasmas Prepared on the Surfaces of Complex and Atomic Targets 18

2.2 Nonperturbative HHG in Indium Plasma: Theory of Resonant Recombination 22

2.2.1 Principles ofTheory 22

2.2.2 Discussion 24

2.2.3 Important Consequences 27

2.3 Simulation of Resonant High-Order Harmonic Generation in Three-Dimensional Fullerenelike System by Means of Multiconfigurational Time-Dependent Hartree–Fock Approach 29

2.3.1 Basics of the Nonlinear Optical Studies of Fullerenes 29

2.3.2 Simulations and Discussion 32

2.4 Endohedral Fullerenes: AWay to Control Resonant HHG 35

2.4.1 Theoretical Approach and Details of Computation 37

2.4.2 Results of Simulations and Discussion 39

References 43

3 Comparison of Resonance Harmonics: Experiment and Theory 47

3.1 Experimental and Theoretical Studies of Two-Color Pump Resonance-Induced Enhancement of Odd and Even Harmonics from a Tin Plasma 47

3.1.1 Experimental Studies 48

3.1.2 Theoretical Approach 52

3.2 Comparative Studies of Resonance Enhancement of Harmonic Radiation in Indium Plasma Using Multicycle and Few-Cycle Pulses 58

3.2.1 Introduction 58

3.2.2 Indium Emission Spectra in the Cases of 40 and 3.5 fs Driving Pulses 60

3.2.3 Testing the Indium Emission Spectra Obtained Using 3.5 fs Pulses 64

3.2.4 Theoretical Consideration of the Microscopic Response 67

3.2.5 Experimental Studies of Harmonic Yield on the CEP of Laser Pulse 70

3.2.6 Discussion 73

3.3 Indium Plasma in the Single- and Two-Color Near-Infrared Fields:Enhancement of Tunable Harmonics 76

3.3.1 Description of Problem 76

3.3.2 Experimental Arrangements for HHG in Indium Plasma Using Tunable NIR Pulses 77

3.3.3 Experimental Studies of the Resonance Enhancement of NIR-Induced Harmonics in the Indium Plasma 80

3.3.4 Theory of the Process 86

3.3.5 Discussion and Comparison ofTheory and Experiment 91

3.4 Resonance Enhancement of Harmonics in Laser-Produced Zn II and Zn III Containing Plasmas Using Tunable Near-Infrared Pulses 95

3.4.1 Single- and Two-Color Pumps of Zinc Plasma 95

3.4.2 Modification of Harmonic Spectra at Excitation of Neutrals and Doubly Charged Ions of Zn 97

3.4.3 Peculiarities of HHG in Zinc Plasma Using Tunable Pulses 100

3.5 Application of Tunable NIR Radiation for Resonance Enhancement of Harmonics in Tin, Antimony, and Chromium Plasmas 105

3.5.1 Experimental Results 105

3.5.2 Theoretical Analysis of Resonance-Enhanced Harmonic Spectra from Sn, Sb, and Cr Plasmas 113

3.5.3 Discussion 118

3.6 Model of Resonant High Harmonic Generation in Multi-Electron Systems 120

3.6.1 Theory 121

3.6.2 Calculations 127

3.6.3 Experiment 131

References 134

4 Resonance Enhancement of Harmonics in Metal-Ablated Plasmas: Early Studies 139

4.1 Indium Plasma: Ideal Source for Strong Single Enhanced Harmonic 139

4.1.1 Strong Resonance Enhancement of Single Harmonic Generated in Extreme Ultraviolet Range 139

4.1.2 Chirp-Induced Enhancement of Harmonic Generation from Indium-Containing Plasmas 143

4.1.2.1 Preparation of the Optimal Plasmas 145

4.1.2.2 Optimization of High Harmonic Generation 148

4.1.2.3 Chirp Control 150

4.1.2.4 Discussion 152

4.2 Harmonic Generation from Different Metal Plasmas 158

4.2.1 Chromium Plasma: Sample for Enhancement and Suppression of Harmonics 158

4.2.2 Studies of Resonance-Induced Single Harmonic Enhancement in Manganese, Tin, Antimony, and Chromium Plasmas 161

4.2.2.1 Manganese Plasma 162

4.2.2.2 Chromium Plasma 164

4.2.2.3 Antimony Plasma 167

4.2.2.4 Tin Plasma 169

4.2.2.5 Discussion of Harmonic Enhancement 170

4.2.3 Enhancement of High Harmonics from Plasmas Using Two-Color Pump and Chirp Variation of 1 kHz Ti:Sapphire Laser Pulses 172

4.2.3.1 Advances in Using High Pulse Repetition Source for HHG in Plasmas 172

4.2.3.2 Comparison of Plasmas Allowing Generation of Featureless and Resonance-Enhanced HHG Spectra 173

4.2.3.3 Discussion 179

4.3 Peculiarities of Resonant and Nonresonant Harmonics Generating in Laser-Produced Plasmas 181

4.3.1 Spatial Coherence Measurements of Nonresonant and Resonant High-Order Harmonics Generated in Different Plasmas 181

4.3.1.1 Introduction 181

4.3.1.2 Measurements of the Spatial Coherence of Harmonics 182

4.3.2 Demonstration of the 101st Harmonic Generation from Laser-Produced Manganese Plasma 188

4.3.2.1 Low Cutoffs from Plasma Harmonics 188

4.3.2.2 Experimental Arrangements and Initial Research 189

4.3.2.3 Analysis of Cutoff Extension 193

4.3.3 Isolated Subfemtosecond XUV Pulse Generation in Mn Plasma Ablation 198

4.3.3.1 Application of a Few-Cycle Pulses for Harmonic Generation in Plasmas: Experiments with Manganese Plasma 198

4.3.3.2 Theoretical Calculations and Discussion 202

References 207

5 Resonance Processes in Ablated Semiconductors 213

5.1 High-Order Harmonic Generation During Propagation of Femtosecond PulsesThrough the Laser-Produced Plasmas of Semiconductors 215

5.1.1 Optimization of HHG 215

5.1.2 Resonance-Induced Enhancement of Harmonics 217

5.1.3 Two-Color Pump 219

5.1.4 Quasi-Phase-Matching 221

5.1.5 Properties of Semiconductor Plasmas 224

5.1.6 Harmonic Cutoffs 225

5.2 27th Harmonic Enhancement by Controlling the Chirp of the Driving Laser Pulse During High-Order Harmonic Generation in GaAs and Te Plasmas 226

5.2.1 Optimization of HHG in GaAs Plasma 227

5.2.2 Variation of the Chirp of Femtosecond Pulses 230

5.2.3 Observation of Single-Harmonic Enhancement Due to Quasi-Resonance with the Tellurium Ion Transition at 29.44 nm 233

5.3 Resonance Enhanced Twenty-First Harmonic Generation in the Laser-Ablation Antimony Plume at 37.67 nm 236

References 239

6 Resonance Processes at Different Conditions of Harmonic Generation in Laser-Produced Plasmas 241

6.1 Application of Picosecond Pulses for HHG 241

6.1.1 High-Order Harmonic Generation of Picosecond Laser Radiation in Carbon-Containing Plasmas 242

6.1.1.1 Experimental Arrangements and Results 242

6.1.1.2 Discussion 250

6.1.2 Resonance Enhancement of the 11th Harmonic of 1064 nm Picosecond Radiation Generating in the Lead Plasma 252

6.1.2.1 Analysis of Resonantly Enhanced 11th Harmonic 253

6.1.2.2 Variation of Resonance Enhancement by Insertion of Gases 258

6.2 Size-Related Resonance Processes Influencing Harmonic Generation in Plasmas 261

6.2.1 Resonance-Enhanced Harmonic Generation in Nanoparticle-Containing Plasmas 261

6.2.1.1 Experimental Arrangements 262

6.2.1.2 In2O3 Nanoparticles 264

6.2.1.3 Mn2O3 Nanoparticles 267

6.2.1.4 Sn Nanoparticles 269

6.2.1.5 Discussion 270

6.2.2 High-Order Harmonic Generation from Fullerenes 271

References 276

7 Comparison of the Resonance-, Nanoparticle-, and Quasi-Phase-Matching-Induced Processes Leading to the Growth of High-Order Harmonic Yield 281

7.1 Introduction 281

7.2 Quasi-Phase-Matched High-Order Harmonic Generation in Laser-Produced Plasmas 283

7.2.1 Experimental Arrangements 284

7.2.2 Experimental Observations of QPM 286

7.2.3 Modeling HHG in Plasma Plumes 290

7.2.4 Discussion and Comparison of Theory and Experiment 296

7.2.4.1 Scenario 1 297

7.2.4.2 Scenario 2 297

7.3 Influence of a Few-Atomic Silver Molecules on the High-Order Harmonic Generation in the Laser-Produced Plasmas 299

7.3.1 Introduction 299

7.3.2 Experimental Setup 300

7.3.3 Harmonic Generation and Morphology of Ablated Materials 301

7.3.4 Discussion 306

7.4 Controlling Single Harmonic Enhancement in Laser-Produced Plasmas 310

7.4.1 On the Method of Harmonic Enhancement 310

7.4.2 Experimental Conditions for Observation of the Control of Harmonic Enhancement 311

7.4.3 Featureless and Resonance-Enhanced Harmonic Distributions 312

7.4.4 Comparison of Plasma and Harmonic Spectra in the LPPs Allowing Generation of Resonantly Enhanced Harmonics 316

7.4.4.1 Zinc Plasma 317

7.4.4.2 Antimony Plasma 319

7.4.4.3 Cadmium Plasma 320

7.4.4.4 Indium Plasma 320

7.4.4.5 Manganese Plasma 321

7.4.5 Basics of AlternativeModel of Enhancement 322

7.5 Comparison of Micro- and Macroprocesses during the High-Order Harmonic Generation in Laser-Produced Plasma 322

7.5.1 Basic Principles of Comparison 322

7.5.2 Results of Comparative Experiments 324

7.5.3 Discussion of Comparative Experiments 333

References 335

Summary 339

Index 347