Table of Contents
Preface v
Introduction 1
Chapter 1 Applications of Mid-infrared Sources for the Study of the High-order Nonlinear Optical Processes in Gases 9
1.1 Architecture of mid-infrared Lasers Used for Harmonic Generation in Gases 9
1.1.1 Various schemes of mid-infrared sources 9
1.1.2 Commercially available source of mid-infrared radiation 12
1.2 High-order Harmonic Generation in Gases Using MIR Pulses 18
1.2.1 Infrared two-color multicycle laser field synthesis for generating an intense attosecond pulse 19
1.2.2 Attosecond nonlinear optics using gigawatt-scale isolated attosecond pulses 24
1.2.3 Generation of coherent radiation in the water window region at 1 kHz repetition rate using a mid-infrared pump source 32
1.2.4 Various approaches in the HHG using MIR pulses 36
1.3 Conclusions to Chapter 1 40
References 42
Chapter 2 Principles of HHG in Laser-produced Plasmas using MIR Pulses 49
2.1 Introduction 49
2.2 High-Order Harmonic Generation in Graphite Plasma Plumes Using 800 urn and MIR Laser Pulses 52
2.2.1 Experimental arrangements 55
2.2.2 HHG at the conditions of stabilized plasma formation 58
2.2.3 Discussion 63
2.3 MIR- and 800-nm-Induced High-Order Harmonic Generation in Uracil Laser Plumes 67
2.3.1 Introduction 67
2.3.2 Experiment and discussion 69
2.4 High-Order Harmonic Generation in Fullerenes Using Few- and Multi-Cycle Pulses of Different Wavelengths 75
2.4.1 Introduction 75
2.4.2 Results and discussion 76
2.5 Conclusions to Chapter 2 85
References 87
Chapter 3 Resonance-induced Enhancement of Harmonics in Metal Plasmas 91
3.1 Resonance Enhancement of Harmonics in Metal Plasmas using Tunable Mid-infrared Pulses 92
3.1.1 Introduction 92
3.1.2 Experimental conditions for HHG in plasma plumes using tunable MIR pulses 93
3.1.3 Experimental studies of resonance enhancement of MIR-induced harmonics in plasmas 95
3.1.4 Theoretical analysis of resonance-enhanced harmonic spectra from Sn, Sb, and Cr plasmas 106
3.1.5 Discussion 112
3.2 Indium Plasma in the Single- and Two-color Mid-infrared Fields: Enhancement of Tunable Harmonics 117
3.2.1 Introduction 117
3.2.2 Experimental studies of the resonance enhancement of MIR-induced harmonics in the indium plasma 120
3.2.3 Theory of resonance enhancement 128
3.2.4 Discussion 133
3.3 Resonance Enhancement of Harmonics in Laser-produced Zn II and Zn III Containing Plasmas 140
3.3.1 Method of laser ablation induced MIR-pumped HHG spectroscopy 140
3.3.2 Experimental conditions of HHG in zinc plasma using tunable MIR pulses 141
3.3.3 Single- and two-color pumps of zinc plasma 143
3.3.4 Modification of harmonic spectra at excitation of neutrals and doubly charged ions of Zn 146
3.3.5 Discussion of results 149
3.4 Conclusions to Chapter 3 157
References 160
Chapter 4 Quasi-phase-matching in Plasmas Using Mid-infrared Pulses 165
4.1 Application of Mid-infrared Pulses for Quasi-phase-matching of High-order Harmonics in Silver Plasma 166
4.1.1 Early studies of quasi-phase-matching 166
4.1.2 Experimental conditions and HHG in silver plasma plumes using tunable 1250-1400 nm, 70 fs pulses under the conditions of quasi-phase-matching 168
4.1.3 Theory of QPM 172
4.2 On- and Off-axis Quasi-phase-matching of the Harmonics Generated in the Multi-jet Laser-produced Plasmas 177
4.2.1 Description of the problem 177
4.2.2 Analysis of on- and off-axis conditions of QPM 180
4.3 Influence of Micro- and Macro-Processes on the High-order Harmonic Generation in Laser-produced Plasma 193
4.3.1 Two concepts of MIR-induced harmonic enhancement 193
4.3.2 Comparative enhancement of harmonics caused by resonance enhancement and QPM 196
4.3.3 Discussion on different methods of harmonic enhancement 208
4.4 Conclusions to Chapter 4 211
References 213
Chapter 5 Various Applications of MIR HHG Approach in Different Plasma Plumes 217
5.1 Ablation of Boron Carbide for High-order Harmonic Generation of Ultrafast Pulses in Laser-produced Plasma 219
5.1.1 Application of hard materials for plasma formation 219
5.1.2 Experimental arrangements 221
5.1.3 Comparison of the plasma and harmonic emission of ablated targets 222
5.1.4 Double-pulse and two-color pump of boron carbide plasma 225
5.1.5 Different schemes of the two-color pump of plasma 227
5.1.6 Influence of ionic resonances on the harmonic yield 231
5.1.7 Discussion of experiments 232
5.2 Two-color High-order Harmonic Generation in Plasmas: Efficiency Dependence on the Generating Particle Properties 235
5.2.1 HHG using single-color and two-color pumps 237
5.2.2 Microscopic response 240
5.2.3 Macroscopic response 247
5.3 High-order Sum and Difference Frequencies Generation Using Tunable Two- and Three-color Commensurate and Incommensurate Mid-infrared Pumps of Graphite Plasma 252
5.3.1 Interaction of commensurate and incommensurate waves in the nonlinear media 252
5.3.2 Experimental results 254
5.3.3 Discussion 263
5.4 Conclusions to Chapter 5 266
References 269
Summary: Perspectives 273
Index 281
