Claude Rulliere (Ed.) Femtosecond Laser Pulses Principles and Experiments Second Edition With 296 Figures,Including 3 Color Plates, and Numerous Experiments ②Springer
Claude Rulliere (Ed.) ` Femtosecond Laser Pulses Principles and Experiments Second Edition With 296 Figures, Including 3 Color Plates, and Numerous Experiments
Preface This is the second edition of this advanced textbook written for scientists who require further training in femtosecond science.Four years after publi- cation of the first edition,femtosecond science has overcome new challenges and new application fields have become mature.It is necessary to take into account these new developments.Two main topics merged during this period that support important scientific activities:attosecond pulses are now gener- 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 fields;two new chap- ters are in this second edition:"Coherent Control in Atoms,Molecules,and Solids"(Chap.11)and "Attosecond Pulses"(Chap.12)with well-documented references. Some changes,addenda,and new references are introduced in the first edition's ten original chapters to take into account new developments and update this advanced textbook which is the result of a scientific adventure that 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 scientific 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. After proposals from different institutions,Universite Bordeaux I and our laboratory were finally selected to ensure the success of this new centre.Since the scientists involved were located throughout France,it was decided that the training courses should be concentrated into a short period of at least 5 days.It is certainly a challenge to give a good grounding in the science of femtosecond pulses in such a short period to scientists who do not necessarily have the required scientific background and are in some cases involved only as users of these pulses as a tool.To start,we contacted well-known specialists from the French femtosecond community;we are very thankful that they showed enthusiasm and immediately started work on this fascinating project
Preface This is the second edition of this advanced textbook written for scientists who require further training in femtosecond science. Four years after publication of the first edition, femtosecond science has overcome new challenges and new application fields have become mature. It is necessary to take into account these new developments. Two main topics merged during this period that support important scientific activities: attosecond pulses are now generated 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 fields; two new chapters are in this second edition: “Coherent Control in Atoms, Molecules, and Solids” (Chap. 11) and “Attosecond Pulses” (Chap. 12) with well-documented references. Some changes, addenda, and new references are introduced in the first edition’s ten original chapters to take into account new developments and update this advanced textbook which is the result of a scientific adventure that 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 scientific 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. After proposals from different institutions, Universit´e Bordeaux I and our laboratory were finally selected to ensure the success of this new centre. Since the scientists involved were located throughout France, it was decided that the training courses should be concentrated into a short period of at least 5 days. It is certainly a challenge to give a good grounding in the science of femtosecond pulses in such a short period to scientists who do not necessarily have the required scientific background and are in some cases involved only as users of these pulses as a tool. To start, we contacted well-known specialists from the French femtosecond community; we are very thankful that they showed enthusiasm and immediately started work on this fascinating project
vi Preface Our adventure began in 1992 and each year since,generally in spring, we have organized a one-week femtosecond training course at the Bordeaux University.Each morning of the course is devoted to theoretical lectures con- cerning different aspects of femtosecond pulses;the afternoons are spent in the laboratory,where a very simple experimental demonstration illustrates each point developed in the morning lectures.At the end of the afternoon,the saturation threshold of the attendees is generally reached,so the evenings are devoted to discovering Bordeaux wines and vineyards,which helps the other- wise shy attendees enter into discussions concerning femtosecond science. A document including all the lectures is always distributed to the partici- pants.Step by step this document has been improved as a result of feedback from the attendees and lecturers,who were forced to find pedagogic answers to the many questions arising during the courses.The result is a very com- prehensive textbook that we decided to make available to the wider scientific community;i.e.,the result is this book. The people who will gain the most from this book are the scientists(grad- uate students,engineers,researchers)who are not necessarily trained as laser scientists but who want to use femtosecond pulses and/or gain a real under- standing of this tool.Laser specialists will also find the book useful,particu- larly if they have to teach the subject to graduate or PhD students.For every reader,this book provides a simple progressive and pedagogic approach to this field.It is particularly enhanced by the descriptions of basic experiments or exercises that can be used for further study or practice. The first chapter simply recalls the basic laser principles necessary to un- derstand the generation process of ultrashort pulses.The second chapter is a brief introduction to the basics behind the experimental problems generated by ultrashort laser pulses when they travel through different optical devices or samples.Chapter 3 describes how ultrashort pulses are generated indepen- dently of the laser medium.In Chaps.4 and 5 the main laser sources used to generate ultrashort laser pulses and their characteristics are described. Chapter 6 presents the different methods currently used to characterize these pulses,and Chap.7 describes how to change these characteristics (pulse dura- tion,amplification,wavelength tuning,etc.).The rest of the book is devoted to applications,essentially the different experimental methods based on the use of ultrashort laser pulses.Chapter 8 describes the principal spectroscopic methods,presenting some typical results,and Chap.9 addresses mainly the problems that may arise when the pulse duration is as short as the coherence time of the sample being studied.Chapter 10 describes typical applications of ultrashort laser pulses for the characterisation of electronic devices and the electromagnetic pulses generated at low frequency.Chapter 11 is an overview of the coherent control physical processes making it possible to control evo- lution channels in atoms,molecules and solids.Several examples of oriented reactions in this chapter illustrate the possible applications of such a tech- nique.Chapter 12 introduces the attosecond pulse generation by femtosecond pulse-matter interaction.It is designed for a best understanding of the physics
vi Preface Our adventure began in 1992 and each year since, generally in spring, we have organized a one-week femtosecond training course at the Bordeaux University. Each morning of the course is devoted to theoretical lectures concerning different aspects of femtosecond pulses; the afternoons are spent in the laboratory, where a very simple experimental demonstration illustrates each point developed in the morning lectures. At the end of the afternoon, the saturation threshold of the attendees is generally reached, so the evenings are devoted to discovering Bordeaux wines and vineyards, which helps the otherwise shy attendees enter into discussions concerning femtosecond science. A document including all the lectures is always distributed to the participants. Step by step this document has been improved as a result of feedback from the attendees and lecturers, who were forced to find pedagogic answers to the many questions arising during the courses. The result is a very comprehensive textbook that we decided to make available to the wider scientific community; i.e., the result is this book. The people who will gain the most from this book are the scientists (graduate students, engineers, researchers) who are not necessarily trained as laser scientists but who want to use femtosecond pulses and/or gain a real understanding of this tool. Laser specialists will also find the book useful, particularly if they have to teach the subject to graduate or PhD students. For every reader, this book provides a simple progressive and pedagogic approach to this field. It is particularly enhanced by the descriptions of basic experiments or exercises that can be used for further study or practice. The first chapter simply recalls the basic laser principles necessary to understand the generation process of ultrashort pulses. The second chapter is a brief introduction to the basics behind the experimental problems generated by ultrashort laser pulses when they travel through different optical devices or samples. Chapter 3 describes how ultrashort pulses are generated independently of the laser medium. In Chaps. 4 and 5 the main laser sources used to generate ultrashort laser pulses and their characteristics are described. Chapter 6 presents the different methods currently used to characterize these pulses, and Chap. 7 describes how to change these characteristics (pulse duration, amplification, wavelength tuning, etc.). The rest of the book is devoted to applications, essentially the different experimental methods based on the use of ultrashort laser pulses. Chapter 8 describes the principal spectroscopic methods, presenting some typical results, and Chap. 9 addresses mainly the problems that may arise when the pulse duration is as short as the coherence time of the sample being studied. Chapter 10 describes typical applications of ultrashort laser pulses for the characterisation of electronic devices and the electromagnetic pulses generated at low frequency. Chapter 11 is an overview of the coherent control physical processes making it possible to control evolution channels in atoms, molecules and solids. Several examples of oriented reactions in this chapter illustrate the possible applications of such a technique. Chapter 12 introduces the attosecond pulse generation by femtosecond pulse-matter interaction. It is designed for a best understanding of the physics
Preface vii principles sustaining attosecond pulse creation as well as the encountered dif- ficulties in such processes. I would like to acknowledge all persons and companies whose names do not directly appear in this book but whose participation has been essential to the final goal of this adventure.My colleague Gediminas Jonusauskas was greatly involved in the design of the experiments presented during the courses and at the end of the chapters in this book.Daniele Hulin,Jean-Rene Lalanne and Arnold Migus gave much time during the initial stages,particularly in writing the first version of the course document.The publication of this book would not have been possible without their important support and contri- bution.My colleagues Eric Freysz,Frangois Dupuy,Frederic Adamietz and Patricia Segonds also participated in the organization of the courses,as did the post-doc and PhD students Anatoli Ivanov,Corinne Rajchenbach,Emmanuel Abraham,Bruno Chassagne and Benoit Lourdelet. Essential financial support and participation in the courses,particularly by the loan of equipment,came from the following laser or optics companies: B.M.Industries,Coherent France,Hamamatsu France,A.R.P.Photonetics, Spectra-Physics France,Optilas,Continuum France,Princeton Instruments SA and Quantel France. I hope that every reader will enjoy reading this book.The best result would be if they conclude that femtosecond pulses are wonderful tools for scientific investigation and want to use them and know more. Bordeaux,April 2004 Claude Rulliere
Preface vii principles sustaining attosecond pulse creation as well as the encountered dif- ficulties in such processes. I would like to acknowledge all persons and companies whose names do not directly appear in this book but whose participation has been essential to the final goal of this adventure. My colleague Gediminas Jonusauskas was greatly involved in the design of the experiments presented during the courses and at the end of the chapters in this book. Dani`ele Hulin, Jean-Ren´e Lalanne and Arnold Migus gave much time during the initial stages, particularly in writing the first version of the course document. The publication of this book would not have been possible without their important support and contribution. My colleagues Eric Freysz, Fran¸cois Dupuy, Frederic Adamietz and Patricia Segonds also participated in the organization of the courses, as did the post-doc and PhD students Anatoli Ivanov, Corinne Rajchenbach, Emmanuel Abraham, Bruno Chassagne and Benoit Lourdelet. Essential financial support and participation in the courses, particularly by the loan of equipment, came from the following laser or optics companies: B.M. Industries, Coherent France, Hamamatsu France, A.R.P. Photonetics, Spectra-Physics France, Optilas, Continuum France, Princeton Instruments SA and Quantel France. I hope that every reader will enjoy reading this book. The best result would be if they conclude that femtosecond pulses are wonderful tools for scientific investigation and want to use them and know more. Bordeaux, April 2004 Claude Rulli`ere
Contents Preface .............. Contributors............... ...。。。。。。。。。。。。。。。XV 1 Laser Basics C.Hirlimann.............. 1 1.1 Introduction........ 1 1.2 Stimulated Emission...... 1 1.2.1 Absorption ............................................ 1.2.2 Spontaneous Emission.................................... 3 1.2.3 Stimulated Emission........................... 4 1.3 Light Amplification by Stimulated Emission..................... 4 1.4 Population Inversion.......................................... 5 1.4.1Two-Level System..............… 5 1.4.2 Optical Pumping........................................ 6 1.4.3 Light Amplification...................... 1.5 Amplified Spontaneous Emission (ASE)......................... 10 1.5.1 Amplifier Decoupling..................................... 11 1.6 The Optical Cavity .......................................... 13 1.6.1 The Fabry-Perot Interferometer........................... 13 1.6.2 Geometric Point of View ................................ 14 l.6.3 Diffractive-Optics Point of View........………· 15 1.6.4 Stability of a Two-Mirror Cavity 17 1.6.5 Longitudinal Modes...................................... 20 1.7 Here Comes the Laser!................ 22 1.8 Conclusion ........................ 22 1.9 Problems..........· 22 Further Reading ....... 23 Historial References ...... 23
Contents Preface ........................................................ v Contributors ................................................... xv 1 Laser Basics C. Hirlimann .................................................... 1 1.1 Introduction ................................................. 1 1.2 Stimulated Emission .......................................... 1 1.2.1 Absorption ............................................. 3 1.2.2 Spontaneous Emission .................................... 3 1.2.3 Stimulated Emission ..................................... 4 1.3 Light Amplification by Stimulated Emission ..................... 4 1.4 Population Inversion .......................................... 5 1.4.1 Two-Level System ....................................... 5 1.4.2 Optical Pumping ........................................ 6 1.4.3 Light Amplification ...................................... 8 1.5 Amplified Spontaneous Emission (ASE) . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.5.1 Amplifier Decoupling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.6 The Optical Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.6.1 The Fabry–P´erot Interferometer . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.6.2 Geometric Point of View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 1.6.3 Diffractive-Optics Point of View . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.6.4 Stability of a Two-Mirror Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1.6.5 Longitudinal Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.7 Here Comes the Laser! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1.8 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1.9 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Historial References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Contents 2 Pulsed Optics C.Hirlimann... 2.1 Introduction 4444444 25 2.2 Linear Optics 26 2.2.1 Light....... 26 2.2.2 Light Pulses...…………… 28 2.2.3 Relationship Between Duration and Spectral Width.......... 30 2.2.4 Propagation of a Light Pulse in a Transparent Medium....... 32 2.3 Nonlinear Optics.................................. 38 2.3.1 Second-Order Susceptibility............................... 38 2.3.2 Third-Order Susceptibility......... 45 2.4 Cascaded Nonlinearities......................... 444 53 2.5 Problems....… 55 Further Reading...·· 56 56 nCes........。。。。。。。。。.........::::::::。。。。。。 3 Methods for the Generation of Ultrashort Laser Pulses: Mode-Locking A.Ducasse,C.Rulliere and B.Couillaud........................... 57 3.1 Introduction ................................................ 57 3.2 Principle of the Mode-Locked Operating Regime 60 3.3 General Considerations Concerning Mode-Locking................ 66 3.4 The Active Mode-Locking Method........ 67 3.5 Passive and Hybrid Mode-Locking Methods...................... 74 3.6 Self-Locking of the Modes .................................... 81 References.. 87 4 Further Methods for the Generation of Ultrashort Optical Pulses C.Hirlimann..……… 89 41 ntroduction.… 89 4.1.1 Time-Frequency Fourier Relationship 89 4.2 Gas Lasers......…… 91 421Mode-L0 cking… 92 4.2.2 Pulse Compression....................................... 92 4.3 Dye Lasers .............. 94 4.3.1 Synchronously Pumped Dye Lasers.......··· 94 4.3.2 Passive Mode-Locking..... 96 4.3.3 Really Short Pulses ....... ...101 4.3.4 Hybrid Mode-Locking...... ...102 4.8.5 Wavelength Tuning......................................104 4.4 Solid-State Lasers ................................. .....106 4.4.1 The Neodymium1on..........................106 4.4.2 The Titanium Ion ..................................... .107 4.4.3F-Centers....................109
x Contents 2 Pulsed Optics C. Hirlimann .................................................... 25 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2.2 Linear Optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.2.1 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.2.2 Light Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.2.3 Relationship Between Duration and Spectral Width . . . . . . . . . . 30 2.2.4 Propagation of a Light Pulse in a Transparent Medium . . . . . . . 32 2.3 Nonlinear Optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 2.3.1 Second-Order Susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 2.3.2 Third-Order Susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 2.4 Cascaded Nonlinearities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 2.5 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 3 Methods for the Generation of Ultrashort Laser Pulses: Mode-Locking A. Ducasse, C. Rulli`ere and B. Couillaud ........................... 57 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 3.2 Principle of the Mode-Locked Operating Regime . . . . . . . . . . . . . . . . . 60 3.3 General Considerations Concerning Mode-Locking . . . . . . . . . . . . . . . . 66 3.4 The Active Mode-Locking Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 3.5 Passive and Hybrid Mode-Locking Methods. . . . . . . . . . . . . . . . . . . . . . 74 3.6 Self-Locking of the Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 4 Further Methods for the Generation of Ultrashort Optical Pulses C. Hirlimann .................................................... 89 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 4.1.1 Time–Frequency Fourier Relationship . . . . . . . . . . . . . . . . . . . . . . 89 4.2 Gas Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 4.2.1 Mode-Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4.2.2 Pulse Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4.3 Dye Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 4.3.1 Synchronously Pumped Dye Lasers . . . . . . . . . . . . . . . . . . . . . . . . 94 4.3.2 Passive Mode-Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 4.3.3 Really Short Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 4.3.4 Hybrid Mode-Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 4.3.5 Wavelength Tuning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 4.4 Solid-State Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 4.4.1 The Neodymium Ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 4.4.2 The Titanium Ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 4.4.3 F-Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Contents xi 4.4.4 Soliton Laser.................... .......109 4.5 Pulse Generation Without Mode-Locking.... ….111 4.5.1 Distributed Feedback Dye Laser (DFDL)...................111 4.5.2 Traveling-Wave Excitation......... ...112 4.5.3 Space-Time Selection ......................... ....112 4.5.4 Quenched Cavity........................................113 4.6 New Developments.....................114 4.6.1 Diode Pumped Lasers....................................114 4.6.2 Femtosecond Fibber Lasers...............................114 4.6.3 Femtosecond Diode Lasers .....115 4.6.4 New Gain Materials............... ..117 4.7 Trends ................... .118 References..。.… ..119 5 Pulsed Semiconductor Lasers T.Amand and X.Marie................... ...125 5.1 Introduction.................................................125 5.2 Semiconductor Lasers:Principle of Operation....................126 5.2.1 Semiconductor Physics Background........................126 5.2.2 pn Junction -Homojunction Laser ........................129 5.3 Semiconductor Laser Devices......................... .....131 5.3.1 Double-Heterostructure Laser .................. .....132 5.3.2 Quantum Well Lasers......................... ..137 5.3.3 Strained Quantum Well and Vertical-Cavity Surface-Emitting Lasers...................................................139 5.4 Semiconductor Lasers in Pulsed-Mode Operation.................141 5.4.1 Gain-Switched Operation.................................143 5.4.2 Q-Switched Operation....................................150 5.4.3 Mode-Locked Operation... ….159 5.4.4 Mode-Locking by Gain Modulation ........................160 5.4.5 Mode-Locking by Loss Modulation:Passive Mode-Locking by Absorption Saturation...................................163 5.4.6 Prospects for Further Developments........................170 References......................................................172 6 How to Manipulate and Change the Characteristics of Laser Pulses f.Saln..............................................175 6.1 Introduction........... ...175 6.2 Pulse Compression.....·..· .175 6.3Amplification................................................178 6.4 Wavelength Tunability ........................................185 6.4.1 Second-and Third-Harmonic Generation.......... ...186 6.4.2 Optical Parametric Generators (OPGs)and Amplifiers (OPAs)187 6.5 Conclusion..........192
Contents xi 4.4.4 Soliton Laser. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 4.5 Pulse Generation Without Mode-Locking . . . . . . . . . . . . . . . . . . . . . . . . 111 4.5.1 Distributed Feedback Dye Laser (DFDL) . . . . . . . . . . . . . . . . . . . 111 4.5.2 Traveling-Wave Excitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 4.5.3 Space–Time Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 4.5.4 Quenched Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 4.6 New Developments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 4.6.1 Diode Pumped Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 4.6.2 Femtosecond Fibber Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 4.6.3 Femtosecond Diode Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 4.6.4 New Gain Materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 4.7 Trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 5 Pulsed Semiconductor Lasers T. Amand and X. Marie .......................................... 125 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 5.2 Semiconductor Lasers: Principle of Operation . . . . . . . . . . . . . . . . . . . . 126 5.2.1 Semiconductor Physics Background . . . . . . . . . . . . . . . . . . . . . . . . 126 5.2.2 pn Junction – Homojunction Laser . . . . . . . . . . . . . . . . . . . . . . . . 129 5.3 Semiconductor Laser Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 5.3.1 Double-Heterostructure Laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 5.3.2 Quantum Well Lasers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 5.3.3 Strained Quantum Well and Vertical-Cavity Surface-Emitting Lasers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 5.4 Semiconductor Lasers in Pulsed-Mode Operation . . . . . . . . . . . . . . . . . 141 5.4.1 Gain-Switched Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 5.4.2 Q-Switched Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 5.4.3 Mode-Locked Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 5.4.4 Mode-Locking by Gain Modulation . . . . . . . . . . . . . . . . . . . . . . . . 160 5.4.5 Mode-Locking by Loss Modulation: Passive Mode-Locking by Absorption Saturation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 5.4.6 Prospects for Further Developments. . . . . . . . . . . . . . . . . . . . . . . . 170 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 6 How to Manipulate and Change the Characteristics of Laser Pulses F. Salin ........................................................ 175 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 6.2 Pulse Compression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 6.3 Amplification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 6.4 Wavelength Tunability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 6.4.1 Second- and Third-Harmonic Generation . . . . . . . . . . . . . . . . . . . 186 6.4.2 Optical Parametric Generators (OPGs) and Amplifiers (OPAs) 187 6.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
xii Contents 6.6 Problems..............192 eference8................................................l93 7 How to Measure the Characteristics of Laser Pulses L.Sarger and J.Oberle...........................................195 7.1 Introduction...........................195 7.2 Energy Measurements.........................................196 7.3 Power Measurements .........................................197 7.4 Measurement of the Pulse Temporal Profile............. .198 7.4.1 Pure Electronic Methods.................................198 7.4.2All-0 ptical Methods..................202 7.5 Spectral Measurements........................................215 7.6 Amplitude-Phase Measurements...............................216 7.6.1 FROG Technique............................... .217 7.6.2 Frequency Gating .218 7.6.3 Spectal Interferometry and SPIDER........ .219 References ........................................ .221 8 Spectroscopic Methods for Analysis of Sample Dynamics C.Rulliere,T.Amand and X.Marie...............................223 8.1 Introduction.................................................223 8.2 "Pump-Probe"Methods......................................224 8.2.1 General Principles......................224 8.2.2 Time-Resolved Absorption in the UV-Visible Spectral Domain 225 8.2.3 Time-Resolved Absorption in the IR Spectral Domain ..233 8.2.4 Pump-Probe Induced Fluorescence........................235 8.2.5 Probe-Induced Raman Scattering..........................237 8.2.6 Coherent Anti-Stokes Raman Scattering (CARS) …….241 8.3 Time-Resolved Emission Spectroscopy:Electronic Methods........249 8.3.1 Broad-Bandwidth Photodetectors..........................250 8.3.2 The Streak Camera......................................250 8.3.3 "Single"-Photon Counting................................250 8.4 Time-Resolved Emission Spectroscopy:Optical Methods...........252 8.4.1 The Kerr Shutter........................................252 8.4.2 Up-conversion Method 。。。。。 8.5 Time-Resolved Spectroscopy by Excitation Correlation............260 8.5.1 Experimental Setup......................................261 8.5.2 Interpretation of the Correlation Signal.....................262 8.5.3 Example of Application......................... ....263 8.6 Transient-Grating Techniques........................ ......264 8.6.1 Principle of the Method:Degenerate Four-Wave Mixing (DFWM)........... ……….264 8.6.2 Example of Application:t-Stilbene Molecule ................266 8.6.3 Experimental Tricks.....................................269 8.7 Studies Using the Kerr Effect ..................................270
xii Contents 6.6 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 7 How to Measure the Characteristics of Laser Pulses L. Sarger and J. Oberl´e ........................................... 195 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 7.2 Energy Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 7.3 Power Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 7.4 Measurement of the Pulse Temporal Profile . . . . . . . . . . . . . . . . . . . . . . 198 7.4.1 Pure Electronic Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 7.4.2 All-Optical Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 7.5 Spectral Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 7.6 Amplitude–Phase Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 7.6.1 FROG Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 7.6.2 Frequency Gating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 7.6.3 Spectal Interferometry and SPIDER . . . . . . . . . . . . . . . . . . . . . . . 219 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 8 Spectroscopic Methods for Analysis of Sample Dynamics C. Rulli`ere, T. Amand and X. Marie ............................... 223 8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 8.2 “Pump–Probe” Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 8.2.1 General Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 8.2.2 Time-Resolved Absorption in the UV–Visible Spectral Domain 225 8.2.3 Time-Resolved Absorption in the IR Spectral Domain . . . . . . . . 233 8.2.4 Pump–Probe Induced Fluorescence . . . . . . . . . . . . . . . . . . . . . . . . 235 8.2.5 Probe-Induced Raman Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . 237 8.2.6 Coherent Anti-Stokes Raman Scattering (CARS) . . . . . . . . . . . . 241 8.3 Time-Resolved Emission Spectroscopy: Electronic Methods . . . . . . . . 249 8.3.1 Broad-Bandwidth Photodetectors. . . . . . . . . . . . . . . . . . . . . . . . . . 250 8.3.2 The Streak Camera . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 8.3.3 “Single”-Photon Counting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 8.4 Time-Resolved Emission Spectroscopy: Optical Methods. . . . . . . . . . . 252 8.4.1 The Kerr Shutter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 8.4.2 Up-conversion Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 8.5 Time-Resolved Spectroscopy by Excitation Correlation . . . . . . . . . . . . 260 8.5.1 Experimental Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 8.5.2 Interpretation of the Correlation Signal . . . . . . . . . . . . . . . . . . . . . 262 8.5.3 Example of Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 8.6 Transient-Grating Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 8.6.1 Principle of the Method: Degenerate Four-Wave Mixing (DFWM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 8.6.2 Example of Application: t-Stilbene Molecule . . . . . . . . . . . . . . . . 266 8.6.3 Experimental Tricks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 8.7 Studies Using the Kerr Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
Contents xiji 8.7.1 Kerr "Ellipsometry".....................................270 8.8 Laboratory Demonstrations....................................273 8.8.1 How to Demonstrate Pump-Probe Experiments Directly.....273 8.8.2 How to Observe Generation of a CARS Signal by Eye........276 8.8.3 How to Build a Kerr Shutter Easily for Demonstration.......278 8.8.4 How to Observe a DFWM Diffraction Pattern Directly.......279 References..............................280 9 Coherent Effects in Femtosecond Spectroscopy:A Simple Picture Using the Bloch Equation M.Joffre.......................................................283 91 ntroduction.....................283 9.2 Theoretical Model......………… .283 9.2.1 Equation of Evolution....................................284 9.2.2 Perturbation Theory .....286 9.2.3 Two-Level Model....... ...289 9.2.4 Induced Polarization .....................................290 9.3 Applications to Femtosecond Spectroscopy.......................291 9.3.1 First Order ................... .291 9.3.2 Second Order ................. ….292 9.3.3 Third Order ..296 9.4 Multidimensional Spectroscopy........... ...304 9.5 Conclusion…… .306 9.6 Problems........................................ ··..306 References。。 ...307 10 Terahertz Femtosecond Pulses A.Bonvalet and M.Joffre ........................................309 10.1 Introduction................................................309 10.2 Generation of Terahertz Pulses................................310 10.2.1 Photoconductive Switching.............................311 10.2.2 Optical Rectification in a Nonlinear Medium..............314 10.3 Measurement of Terahertz Pulses..............................316 10.3.1 Fourier Transform Spectroscopy.........................316 10.3.2 Photoconductive Sampling..............................319 10.3.3 Free-Space Electro-Optic Sampling ..319 10.4 Some Experimental Results...................................321 10.5 Time-Domain Terahertz Spectroscopy..........................325 10.6 Conclusion.............. ....326 10.7 Problems ......... ..329 References...·.·······… .330
Contents xiii 8.7.1 Kerr “Ellipsometry” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 8.8 Laboratory Demonstrations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 8.8.1 How to Demonstrate Pump–Probe Experiments Directly . . . . . 273 8.8.2 How to Observe Generation of a CARS Signal by Eye . . . . . . . . 276 8.8.3 How to Build a Kerr Shutter Easily for Demonstration . . . . . . . 278 8.8.4 How to Observe a DFWM Diffraction Pattern Directly . . . . . . . 279 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 9 Coherent Effects in Femtosecond Spectroscopy: A Simple Picture Using the Bloch Equation M. Joffre ....................................................... 283 9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 9.2 Theoretical Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 9.2.1 Equation of Evolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 9.2.2 Perturbation Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 9.2.3 Two-Level Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 9.2.4 Induced Polarization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 9.3 Applications to Femtosecond Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . 291 9.3.1 First Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 9.3.2 Second Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 9.3.3 Third Order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 9.4 Multidimensional Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 9.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306 9.6 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 10 Terahertz Femtosecond Pulses A. Bonvalet and M. Joffre ........................................ 309 10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 10.2 Generation of Terahertz Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 10.2.1 Photoconductive Switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 10.2.2 Optical Rectification in a Nonlinear Medium . . . . . . . . . . . . . . 314 10.3 Measurement of Terahertz Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 10.3.1 Fourier Transform Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . 316 10.3.2 Photoconductive Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 10.3.3 Free-Space Electro-Optic Sampling . . . . . . . . . . . . . . . . . . . . . . 319 10.4 Some Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 10.5 Time-Domain Terahertz Spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . 325 10.6 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 10.7 Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
xiv Contents 11 Coherent Control in Atoms,Molecules and Solids T.Amand,V.Blanchet,B.Girard and X.Marie....................333 1l.1 ntroduction...............333 11.2 Coherent Control in the Frequency Domain........... .....334 11.3 Temporal Coherent Control......................... .....339 11.3.1 Principles of Temporal Coherent Control.................339 11.3.2 Temporal Coherent Control in Solid State Physics.........347 11.4 Coherent Control with Shaped Laser Pulses.....................356 11.4.1 Generation of Chirped or Shaped Laser Pulses .357 11.4.2 Coherent Control with Chirped Laser Pulses..............360 11.4.3 Coherent Control with Shaped Laser Pulses...............365 11.5 Coherent Control in Strong Field....................... .374 11.6 Conclusic0n......… .385 References.......··· ..387 12 Attosecond Pulses E.Constant and E.Mevel............................. ··.395 12.1 Introduction...................…… ··....395 12.2 High-Order Harmonic Generation:A Coherent,Short-Pulse XUV Source................................................396 12.3 Semiclassical Picture of HHG.................................398 12.3.1 Atomic Ionization in the Tunnel Domain .....399 12.3.2 Electronic Motion in an Electric Field....................400 12.3.3 Semiclassical View of HHG.............................402 12.4 High-Order Harmonic Generation as an Attosecond PulseSource................................................405 12.4.1 Emission of an Isolated Attosecond Pulse.................408 12.5 Techniques for Measurement of Attosecond Pulses...............412 12.5.1 Cross Correlation......................................412 12.5.2 Laser Streaking.................414 12.5.3 Autocorrelation.................415 12.5.4 XUV-induced Nonlinear Processes ............. ..416 12.5.5 Splitting,Delay Control and Recombination of Attosecond Pulses.....................................416 12.6 Applications of Attosecond Pulses .............................417 12.7Conclusion..................................................419 References..............419 Index.。 …….423
xiv Contents 11 Coherent Control in Atoms, Molecules and Solids T. Amand, V. Blanchet, B. Girard and X. Marie .................... 333 11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 11.2 Coherent Control in the Frequency Domain . . . . . . . . . . . . . . . . . . . . . 334 11.3 Temporal Coherent Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 11.3.1 Principles of Temporal Coherent Control . . . . . . . . . . . . . . . . . 339 11.3.2 Temporal Coherent Control in Solid State Physics . . . . . . . . . 347 11.4 Coherent Control with Shaped Laser Pulses . . . . . . . . . . . . . . . . . . . . . 356 11.4.1 Generation of Chirped or Shaped Laser Pulses . . . . . . . . . . . . 357 11.4.2 Coherent Control with Chirped Laser Pulses . . . . . . . . . . . . . . 360 11.4.3 Coherent Control with Shaped Laser Pulses . . . . . . . . . . . . . . . 365 11.5 Coherent Control in Strong Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 11.6 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 12 Attosecond Pulses E. Constant and E. M´evel ......................................... 395 12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 12.2 High-Order Harmonic Generation: A Coherent, Short-Pulse XUV Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 396 12.3 Semiclassical Picture of HHG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 12.3.1 Atomic Ionization in the Tunnel Domain . . . . . . . . . . . . . . . . . 399 12.3.2 Electronic Motion in an Electric Field . . . . . . . . . . . . . . . . . . . . 400 12.3.3 Semiclassical View of HHG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 12.4 High-Order Harmonic Generation as an Attosecond Pulse Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 12.4.1 Emission of an Isolated Attosecond Pulse . . . . . . . . . . . . . . . . . 408 12.5 Techniques for Measurement of Attosecond Pulses . . . . . . . . . . . . . . . 412 12.5.1 Cross Correlation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 12.5.2 Laser Streaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 12.5.3 Autocorrelation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 12.5.4 XUV-induced Nonlinear Processes . . . . . . . . . . . . . . . . . . . . . . . 416 12.5.5 Splitting, Delay Control and Recombination of Attosecond Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 12.6 Applications of Attosecond Pulses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 12.7 Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419 Index .......................................................... 423
