Ultrafast Laser Nanostructuring: The Pursuit of Extreme Scales

Preface
Contents
Contributors
Volume 1
Part I Fundamental Processes
1 Insights into Laser-Matter Interaction from Inside: Wealth of Processes, Multiplicity of Mechanisms and Possible Roadmaps for Energy Localization
1 Introduction
2 Fundamental Mechanisms of Ultrashort Laser Pulses with Solids
2.1 Mechanisms of Laser Energy Absorption: Role of Dynamic Reflectivity
2.2 Nonequilibrium States: Thermalization of the Excited Systems
2.3 Electromagnetic Processes
2.3.1 Classical Diffraction Limit and Spectral Dispersion
2.3.2 Optical Kerr Effect
2.3.3 Light Defocusing in Dielectrics
2.3.4 Excitation of Electrons in Bandgap Materials
2.3.5 The Role of Laser Polarization in Excitation of Solids
2.3.6 Transient Reduction of Optical Penetration Depth and Light-Induced Metallization
2.3.7 Excitation of Surface Polaritons
2.4 Post-irradiation Material Evolution
2.4.1 Isochoric Heating and Stress Buildup
2.4.2 Melting, Ablation, and Relocation
3 New Insights from TDDFT Simulations
4 Roadmaps for Laser Energy Localization
4.1 Laser Focusing and Beam Shaping
4.2 Spatiotemporal Features of Ultrashort Laser Pulses
4.3 Perspectives of Dual-Wavelength Laser Beams for Material Processing
4.4 Scattering of Light by Nanomaterials
5 Laser-Induced Periodic Surface Structures (LIPSS) as Alternating Localization of Absorbed Laser Energy at Nanoscale
5.1 Highly Regular LIPSS in the Ablative Regime
5.2 Thermochemical LIPSS: Multiplicity of Polaritonic Modes in Thin Films
6 Concluding Remarks
References
2 The Atomistic Perspective of Nanoscale Laser Ablation
1 Introduction
2 Models
2.1 Combined MD-TTM Model for Metals
2.2 Combined MD-nTTM Model for Semiconductors
2.3 Combined MD-nTTM Model for Dielectric Materials
2.4 Optimization of the MD-nTTM Model Performance
2.5 MD-nTTM-CG Model for Materials
2.6 MD-nTTM-U(Te) Model for Materials
2.7 Large-Scale Applications of MD-Based Models
3 Laser-Induced Damage of Solids
3.1 Melting: Heterogeneous and Homogenous
3.2 Ablation and Spallation
3.3 Quality and Efficiency: Mechanical Versus Thermal Damage Regimes
3.4 All-Optical Control in Ultrashort Double-Pulse Laser Ablation Experiments
4 Nanostructuring of Material Surfaces
4.1 Single-Pulse Nanostructuring of Metals
4.2 Periodic Nanostructuring: Theory Versus Experiment
4.3 Periodic Nanostructuring: The Effect of Liquid Environment
5 Inclusion of Plasmonics Into MD-TTM Model
5.1 Generation of LIPSS on Metal Surfaces
5.2 Modeling of LIPSS
5.3 Experimental Verification
6 Conclusion
References
3 Ultrafast Quantum Processes at the Nanoscale: Insights from Modelling
1 Laser-Solid Interaction: Timescales, Quantum, and Quasiclassical/Classical Processes
2 The Generalized Born-Oppenheimer Approximation: Non-Thermal Ions Guided by Excited Electrons
2.1 The Hamiltonian of the Solid
2.2 Born-Oppenheimer (or Adiabatic) Potential Energy Surface (PES)
2.2.1 Adiabatic Approximation
2.3 Effects of a fs-Laser Interaction on Matter
3 Finite-Temperature Density Functional Theory
4 Electronic Temperature-Dependent Interatomic Potentials
5 The Electron-Phonon Coupling: Toward a Thermal State
5.1 Electron-Phonon Coupling Strength
6 Physical Picture of Femtosecond Laser Excitation
7 Ultrafast Structural Phenomena Driven by Quantum or Non-Thermal Effects
8 Open Questions
References
4 The Universality of Self-Organisation: A Path to an AtomPrinter?
1 Introduction
2 The State-of-the-Art Direct Laser Writing Technology
2.1 Additive Manufacturing
2.2 Subtractive Manufacturing
2.3 The Omni-modality Approach: Merging of the Additive and Subtractive Manufacturing
2.4 An Omni-modality Laser to Exploit the Collective Ultrafast Pulse-Matter Interactions
3 Three Fundamental Challenges and Laser-Driven Self-Organisation as a Remedy
3.1 The Fat Fingers Problem (λa0)
3.2 The Explosion of Complexity Problem
3.3 The Mischief of Fluctuations
3.4 Laser-Driven Self-Organisation as a Remedy
3.5 The Promise of Ultrafast Lasers
3.6 Overcoming the Fat Fingers Problem
3.7 Overcoming the Explosion of Complexity
3.8 Taming the Mischief of Fluctuations
4 From Self-Organisation to a 3D Atom Printer
References
5 How Light Drives Material Periodic Patterns Down to the Nanoscale
1 Introduction
2 Self-Organization in Laser-Induced Dissipative Structures
3 Nanoscale Phenomena in Ultrafast LIPSS Formation
3.1 How Light Sees the Nanostructures
3.2 How the Hydrodynamics Creates/Amplifies the Inhomogeneity
4 Universality of LIPSS: From Dielectrics to Metals
4.1 Dielectrics
4.2 Semiconductors and Metals
5 From the Diffraction Limit to the Nanoscale Control of the Periodic Patterns
5.1 From Light Energy Confinement to Thermal Gradients
5.2 How to Drive the Thermal Gradient Direction
6 Conclusion
References
6 In-Situ Observation of the Formation of Laser-Induced Periodic Surface Structures with Extreme Spatial and Temporal Resolution
1 Introduction
2 Time-Resolved XUV Scattering at FLASH
3 Experimental Results
4 Discussion and Interpretation of the Transient Scattering Patterns
5 Polarization Dependence
6 Higher-Order LIPSS
7 Summary and Outlook
References
7 Probing Matter by Light
1 Introduction
1.1 Brief Review of Light Interaction with Matter
1.2 Concept of Probing Matter by Light
2 In-Situ Probing Technique
2.1 Self-Probing: Laser-Induced Breakdown Spectroscopy
2.1.1 Determining Electron Densities of a Laser-Induced Ablation Plasma
2.1.2 Thermodynamic Equilibrium and Determining Electron Temperature
2.1.3 Temporally and Spectrally Resolved Imaging of Laser-Induced Plasmas
2.2 Real-Time Point-Probing with ns and Sub-ns Temporal Resolution
2.3 Ultrafast Point-Probing: From the Visible to the X-Ray Regime
2.4 Ultrafast Surface Microscopy
2.5 Ultrafast Shadowgraphy
2.5.1 Electron Plasma Formation Dynamics Inside Materials
2.5.2 Surface Ablation and Shockwave Expansion
2.6 Ultrafast Continuous Imaging (UCI) Techniques
2.6.1 Spatial Division UCI
2.6.2 Temporal Wavelength Division UCI
2.6.3 Angle Division UCI
2.6.4 Spatial Frequency Division UCI
2.6.5 Receive-Only (Passive) UCI
3 In-Situ Process Monitoring in Technological Laser Processing Applications
3.1 Specificity in Laser Cleaning and Art Restauration
3.2 Monitoring the Depth and Side Wall Smoothness in Laser Drilling
3.3 Welding Quality Control
4 Outlook
References
8 Probing Light by Matter: Implications of Complex Illumination on Ultrafast Nanostructuring
1 Introduction: Traditional Illumination Versus Spatially Structured Light
2 Far-Field Approaches
2.1 Top-Hat Beams
2.2 Annular and Vortex Beams
2.3 Non-diffractive Bessel and Airy Beams
2.4 Holography Approaches
3 Near-Field Approaches
3.1 Plasmonic-Based Approach: SNOM Probes
3.2 Dielectric-Based Approach: Optical-Trap-Assisted Nanopatterning
4 Time-Dependent Structured Profiles
4.1 Dual-Laser Beam Processing (DLBP) and Dual-Laser Additive Manufacturing (DLAM)
4.2 Direct Laser-Interference Patterning (DLIP) and Laser-Induced Forward Transfer (LIFT)
4.3 Resonant Focal Scanning
5 Conclusions and Perspectives
References
9 Imaging Dynamics of Femtosecond Laser-Induced Surface Nanostructuring
1 Introduction of Nanostructuring
2 Selected Ultrafast Imaging Methods
2.1 Ultrafast Optical Imaging
2.2 Ultrafast X-Ray and Electron Diffraction Imaging
3 Ultrafast Pump-Probe Scatter Light Imaging
3.1 Experimental Setup
3.2 Reflectance Measurements
3.3 Characterization of Surface Structures
4 Nanostructuring Imaging Results and Discussions
5 Summary and Outlook
References
Volume 2
Part II Concepts of Extreme Nanostructuring
10 Macroscale Microfabrication Enabled by Nanoscale Morphological Control of Laser Internal Modification
1 Introduction
1.1 Concept of Ultrafast Laser Internal Modification
1.2 Categorization of Typical Morphologies Including Refractive Modification, Nanograting Formation, and Nano-void Formation Induced by Ultrafast Laser Pulses
1.3 Transformation from Self-Organized Nanograting to Preferentially Oriented Nanocracks with Picosecond Laser Pulses of Well-Controlled Pulse Durations
2 Dependence of Nanoscale Morphology on the Pulse Duration of the Ultrafast Laser
2.1 Experimental Setup
2.2 Results
2.3 Discussion
3 Improvement of Longitudinal Resolution with Loosely Focused Picosecond Laser Pulses
3.1 Localized Internal Modification Along the Propagation Direction with Loosely Focused Picosecond Pulses
3.2 Mechanism Investigation
4 Applications
4.1 3D Printing Application
4.2 Flow Chemistry Industrial Application
5 Conclusion and Outlook
References
11 Optical Nanostructuring by Near-Field Laser Ablation
1 Introduction
2 Optical Near Fields of Dielectric Nanostructures
2.1 Dielectric Particles: Theory and Simulations
2.2 Dielectric Particles: Experiments
3 Optical Near Fields of Plasmonic Nanostructures
3.1 Plasmonic Particles: Simulations
3.2 Plasmonic Particles: Experiments
4 Conclusion
References
12 Nanoscale Plasmonic Printing
1 Why Plasmonic?
2 Surface Plasmon Polariton (SPP)
3 Photo-Generated Plasma
3.1 Permittivity Defined by the Electron Density Ne and Collision Rate ν
3.2 Dielectric-to-Metal Transition: Permittivity Analysis
3.3 Energy Deposition at the ENZ Conditions (ps: [/EMC pdfmark [/Subtype /Span /ActualText (epsilon right arrow 0) /StPNE pdfmark [/StBMC pdfmark→0ps: [/EMC pdfmark [/StPop pdfmark [/StBMC pdfmark)
3.4 Electron Photo-Generation
4 Nanoparticles in High Intensity Laser Field
5 Nanolithography by Direct Write with Optical Near Field
6 Localisation of Energy Deposition
7 Conclusions and Outlook
References
13 Search for High-Pressure Silicon Phases: Reaching the Extreme Conditions with High-Intensity Laser Irradiation
1 Introduction
2 Experiment
2.1 Laser Irradiation Conditions
2.2 Irradiated Sample Characterisation
2.2.1 Optical Microscopy
2.2.2 Raman Micro-Spectroscopy
2.2.3 X-Ray Diffraction Analysis with Cu-Kα Radiation
2.2.4 X-Ray Diffraction with 30 KeV Synchrotron Radiation
3 Discussion
3.1 Absorption of Laser Radiation and Ionisation at Relativistic Intensity
3.2 Acceleration of Electrons
3.3 Energy Deposition as Point Explosion
3.4 Spallation from Compressive Stress
4 Conclusions
References
14 Periodic Surface Structures by Laser Interference Ablation
1 Introduction
2 Basic Considerations Concerning Pulse Propagation and Laser Interference Patterns
3 Beam Delivery Methods for Two- and Multi-Beam Interference Ablation
3.1 Imaging Methods
3.2 Non-Imaging Methods
4 Structure Details on the Sub-Period Scale
5 Applications of Periodic Surface Patterns in Optics, Fluidics, Life Science, and Tribology
5.1 Optically/Electromagnetically Effective Applications
5.2 Mechanically/Chemically Effective Applications
6 Perspectives of Laser Interference Ablation
References
15 Spatial Beam Shaping with a Liquid-Crystal Spatial Light Modulator for Surface Micro- and Nanoprocessing
1 Introduction
2 Optical Components for Spatial Beam Shaping
2.1 Classification of Optical Components
2.2 Passive Optical Components for Spatial Beam Shaping
2.3 Active Optical Components for Spatial Beam Shaping
3 Optical Setups for Spatial Beam Shaping with CGH
4 Liquid-Crystal Spatial Light Modulator (LCSLM)
4.1 Important Performance of LCSLM
4.2 Mathematical Model of LCSLM and Its Characteristics
5 Experimental Optical Setups for Holographic Laser Processing
6 Experimental Demonstrations of Holographic Laser Processing
6.1 Parallel Beams Generated with Compensation of LCSLM's Property [44]
6.2 Three Dimensionally Arranged Focusing Spots [46]
6.2.1 Three-Dimensional Microfabrication with Multi-Pulse Irradiations
6.2.2 Three-Dimensional Microfabrication with Single-Pulse Irradiation
6.3 Line-Shaped Beam [47]
6.3.1 Design of a Line-Shaped Beam with a Window Function
6.3.2 Nonparabolic Term
6.3.3 Microfabrications Using a Line Beam
6.4 Vector Beam [41, 48]
6.4.1 Design of Vector Beam
6.4.2 Microfabrications Using a Vector Beam
6.5 Ring-Shaped Beam [49]
6.5.1 Design of Diffraction-Limited Ring-Shaped Beam
6.5.2 Microfabrication Using a Ring Beam
6.5.3 Comparison of Structure Fabricated by Ring-Shaped Beam and Circularly Scanned Beam
6.6 Focused Beam with Sub-Diffraction Limit [50]
6.6.1 Design of Sub-Diffraction Limit Focusing
6.6.2 Microfabrications Using a Sub-Diffraction Limit-Focused Beam
6.6.3 Beam Shaping with the Diffraction Limit Size
7 In-System Optimization of CGH
7.1 Importance of In-System Optimization of CGH
7.2 Pre- and In-Process Optimization of CGH
7.3 In-System and Pre-Processing Optimization of CGH
7.3.1 Optimization of a CGH with More Than 1000 Parallel Beams [58]
7.3.2 Massively Parallel Laser Processing Using In-System Optimization of a CGH
7.4 Parallel Focused Beams with Three-Dimensional Arrangement
7.4.1 Optimization Procedure of CGH
7.4.2 Microfabrication Using a CGH that Performs a 3D Focusing
8 Summary
References
16 Nonstandard Light for Ultrafast Laser Microstructuring and Nanostructuring
1 Introduction
2 Propagation of Non-diffracting Beams in Vacuum: Application to Surface Laser Nanopatterning
2.1 Non-diffracting Beams and Spatial Beam Shaping of Ultrashort Pulses
2.1.1 Basics of Bessel Beams
2.1.2 Spatiotemporal Structure
2.1.3 Presence of Interfaces
2.1.4 Bessel Beam Generation
2.2 Extended Focal Length and Applications to Surface Structuring
3 Non-diffracting Beams for High Aspect Ratio Nano-structuring the Bulk of Transparent Materials
3.1 Propagation in the Bulk of Transparent Dielectrics and Nanoplasma Formation
3.2 Link to the Filamentation of Gaussian Beams
3.3 High Aspect Ratio Index Modification
3.4 High Aspect Ratio Nanovoid Formation
3.4.1 Single-Shot Drilling
3.4.2 Influence of Pulse Duration
3.4.3 Bursts
3.4.4 Pulse Polarization
3.4.5 Heat-Affected Zone
3.5 Physics of Energy Deposition and Void Opening: Current Challenges
4 Applications to High Aspect Ratio Nanostructuring
4.1 Two-Photon Photopolymerization
4.2 Index Modifications and Gratings
4.3 Laser Welding
4.4 Nanovoids for Photonics
4.5 Drilling and Cutting of Glass and Sapphire
4.5.1 Drilling
4.5.2 Transparent Material Separation Without Ablation: Stealth Dicing
4.5.3 Thick Glass Cutting
5 Perspectives
5.1 Crack Formation
5.2 Aberration Correction for Non-flat Glass Cutting
5.3 Laser Processing of Curved Structures
5.4 Bessel-Like Beams and Applications
6 Conclusion
References
17 Controlled Nanostructuring of Transparent Matter with Temporal Airy Pulses
1 Introduction to Nanostructuring of Transparent Matter with Temporally Adapted Pulses
2 Fundamentals of Energy Deposition by Temporally Shaped Femtosecond Laser Pulses into Dielectrics
2.1 Seed and Heat Mechanism by Strong Field and Avalanche Excitation
2.2 Real-Time Spatially Resolved Measurements of Energy Deposition in Water
2.2.1 Optical Properties of Excited Dielectrics
2.2.2 Measuring Optical Properties of Laser-Excited Dielectrics: Imaging Spectral Interferometry
2.2.3 Spatially Resolved Measurement of Laser Excitation in Water with Ultrashort and Temporal Airy Pulses
3 Proof of Principle: Nanostructuring of Solid Dielectrics at the Nanoscale with Temporal Airy Pulses
3.1 Postmortem Measurements of Laser Ablation in Sapphire
3.2 High-Aspect Ratio Ablation Structures in Fused Silica
4 Optoporation of Biological Cells with Temporal Airy Pulses
4.1 Optoporation of Fixed Cells: Efficiency and Morphology
4.2 Optoporation of Living Cells: Survivability
5 Summary and Further Application Opportunities
References
18 Ultraprecise Surface Processing by Etching with Laser-Induced Plasmas
1 Introduction to Ultraprecise Surface Machining with Pulsed Lasers
1.1 Requirements of Ultraprecise Surface Machining for Optical Applications
1.2 Laser-Based Techniques for Ultraprecise Surface Machining
1.3 Laser Polishing
2 Laser-Induced Reactive Plasma Etching
3 Experimental Results on Laser-Induced Plasma Etching
4 Parameter Dependencies of Si and SiO2 Etching
5 Characterization of Etched Surfaces
5.1 Morphology
5.2 Surface Analytics
6 Future Requirements on Ultraprecise Surface Machining
7 Summary and Conclusions
References
19 Nanostructuring by Photochemistry: Laser-Induced Type A Modification
1 Key Properties of Nanostructuring by Photochemistry
1.1 Laser Structuring of Glasses
1.2 The Photosensitive Glasses
1.3 Short State of the Art in Femtosecond Laser-Induced Photochemistry
1.4 Phenomenology of Interaction Processes
2 FPL Glasses
2.1 Glass Composition
2.2 FPL Absorption Spectra
2.3 Intrinsic Luminescence of FPL Glasses
2.4 Femtosecond Laser Inscription in FPL Glass
2.5 Laser Parameter Window for Writing in FPL Glasses
2.6 Temperature Reached During Femtosecond Irradiation
2.7 Inhibition Mechanism of Laser Inscription: Thermal Constraint and UV Co-illumination Scheme
2.8 Distinct DLW Regimes in FPL Glasses Giving Rise to Type A or Type I Glass Modifications
3 Type A Optical Properties
3.1 Refractive Index Modification
3.2 Second-Order Nonlinear Optical Properties (X2)
3.3 The Principal Types of Created Molecular Clusters and Their Luminescent Properties
3.4 Nanoparticle Development by Thermal Annealing Following a Type A Interaction
3.5 Volume Modification: Data Storage
3.6 Integrated Optics: Waveguide, Surface Waveguides, Directional Couplers, Beam Splitters, WBG
3.7 Controlled Nanograting
4 Outlook
References
20 Subtractive 3D Laser Nanolithography of Crystals by Giant Wet-Chemical Etching Selectivity
1 Subtractive 3D Laser Nanostructuring of Materials: Historical Context
1.1 Femtosecond Lasers: Driving Materials Processing
1.2 Initial Approaches to 3D Laser Nanostructuring of Solids
1.2.1 Multiphoton Polymerization (MPP): 3D Printing Nanostructures
1.2.2 The “Microexplosion” Method
1.2.3 Nanograting Phenomena
2 Chemistry Meets Lasers: Laser-Enhanced Wet-Chemical Etching Selectivity
2.1 Differential Wet-Chemical Etching of Crystals
2.2 Wet-Chemical Etching of Impurity Distributions in Crystals
2.3 Wet-Chemical Etching of 3D fs-Pulse Laser-Written Crystals
3 Giant Wet-Etching Selectivity of Nanopores Inside Crystals
3.1 Discovery and First Results
3.2 State-of-the-Art
3.3 Technological Impact
4 Towards the Extreme Scales: The Need for Discovery
References
21 Ultrafast Meets Ultrasmall: Where Are the Limits of Ultrafast Waveguide Writing?
1 Introduction
2 Limitations Associated with Tight Focusing and Nonlinear Propagation in Ultrafast Waveguide Writing
2.1 Linear Effects
2.1.1 Gaussian Beam Focusing
2.1.2 Focusing Through a Planar Air-Dielectric Interface
2.2 Nonlinear Effects: Self-Focusing, Plasma Formation, and Filamentation
2.2.1 Nonlinear Response of the Bound Electrons
2.2.2 Free Carrier Generation
2.2.3 Filamentation
2.3 Practical Strategies for Optimizing the Energy Deposition in the Volume
2.3.1 Pupil Engineering
2.3.2 Simultaneous Spatial and Temporal Focusing
3 Laser-Induced Thermal Processes in the Direct Laser Writing of Waveguides: Virtues and Drawbacks
3.1 The Origin of Thermal Effects
3.2 The Ultrafast Laser Used as a Pure Heat Source
3.2.1 Single-Pulse Irradiation
3.2.2 Multipulse Irradiation
3.3 Limitations Associated with Thermal Processes and Their Possible Workarounds
3.3.1 Self-Annealing of Point Defects: The Example of Fused Silica
3.3.2 Thermal Stress
4 Conclusion
References
22 Multi-Photon 3D Lithography and Calcination for sub-100-nm Additive Manufacturing of Inorganics
Abbreviations
1 Introduction
1.1 Physical Principles of Nano-Localized Photopolymerization
1.2 Chemical Principles of Thresholded Photopolymerization
1.3 Laser 3D Lithography as Nano-Scale Additive Manufacturing
2 Materials and Methods
2.1 Synthesis of Hybrid Materials and Composites
2.2 Thermal Post-Processing Techniques for 3D Nanostructures
3 Trends and Technical Applications
3.1 Micro-Optics
3.2 Nanophotonics
3.3 Micro-Fluidics
3.4 Micro-Mechanics
3.5 Nano-Electronics
3.6 Sub-100-nm Challenges: Comparison of Current Achievements
3.7 Emerging Applications
4 Summary and Conclusions
References
Volume 3
Part III Applications
23 Creation of Material Functions by Nanostructuring
1 Introduction: Laser-Induced Periodic Surface Structures–LIPSS
1.1 Zoology of LIPSS
1.2 Physical and Chemical Properties of LIPSS
2 Applications of LIPSS
2.1 Optical Applications
2.2 Liquid Management and Surface Wetting
2.3 Biological Applications
2.4 Tribological Applications
2.5 Energy Applications
2.6 Other Technical Applications
3 Industrialization
3.1 Market Analysis
3.2 Production Costs
3.3 Patent Situation
4 Outlook
References
24 Role of Surface Chemistry on Wettability of Laser Micro-/Nanostructured Metallic Surfaces
1 Introduction
2 Wettability Transition Upon Ambient Air Exposure
3 Machining Under Controlled Processing Conditions
4 Postprocessing Exposure to Controlled Conditions
4.1 Liquids
4.2 Gases
4.3 Vacuum
5 Heat Treatments
5.1 Air
5.2 Water
6 Fluence
7 Probing Surface Chemistry
8 Conclusion and Future Outlook
References
25 Ultrafast Laser Biomimetic Micro-/Nanostructuring
1 Introduction
2 Functionalities of Patterned Surfaces on Natural Species
3 Laser Fabrication of Biomimetic Structures
3.1 Laser-Induced Periodic Surface Structures (LIPSS)
3.2 Grooves
3.3 Spikes
3.4 Complex Patterns Closer to Biomimetic Features
3.5 Direct Laser Interference Patterning
3.5.1 Fundamentals of DLIP-Based Nanostructuring
3.5.2 Control of Pattern Complexity via DLIP and Double Pulses
4 Tailoring the Nanostructuring Process Through Advanced Predictive Tools
5 Applications of Biomimetic Nanostructures
6 Conclusions-Outlook
References
26 Ultrarapid Industrial Large-Area Processing Using Laser Interference Patterning Methods
1 Introduction
2 Concepts for High-Throughput Processing
2.1 Large-Area Laser Interference Lithography
2.2 Scanner-Based Direct Laser Interference Patterning
2.3 Processing of Embossing Tools
3 Applications of Surface Nanostructures
3.1 Direct Treatment of Dental Implants
3.2 Fabrication of Antibacterial Polymer Foils
3.3 Efficiency Enhancement of Flexible Perovskite Solar Cells by R2R Hot Embossing
3.4 Fabrication of Decorative Elements Using Multi-period Structures
4 Challenges and Future Trends
5 Conclusions and Outlook
References
27 Internal Structuring of Semiconductors with Ultrafast Lasers: Opening a Route to Three-Dimensional SiliconPhotonics
1 Introduction
2 Long-Pulse-Induced Internal Modifications in Semiconductors and Applications
2.1 Nanosecond Laser-Induced Modifications
2.2 Potential Applications
3 Ultrashort-Pulse-Induced Microplasma Formation Inside Silicon and Limitations
3.1 Qualitative Picture and Theoretical Considerations
3.2 Imaging Experiments
3.3 Optical Limitations to Energy Localization
4 Strategies for Enhanced Ultrafast Micro-Excitation Inside Silicon
4.1 Spectral Optimizations up to the Mid-infrared
4.2 Spatial Optimizations up to Extreme Focusing
4.3 Temporal Optimizations for Practical Writing Solutions
5 Emerging Three-Dimensional Solutions for the Semiconductor Industry
5.1 Applications in Microelectronics
5.2 Toward 3D Silicon Photonics
6 Summary and Outlook
References
28 Nanoscale Sampling of Optical Signals: Application to High-Resolution Spectroscopy
1 DLW for Waveguide Fabrication
1.1 Waveguides Based on Type I Modification
1.2 Waveguides Based on Type II Modification
2 DLW for Nano-sampling: Bessel Holes and 3D Antenna
2.1 Fundamental Law of Diffraction Using the Nanograting
2.2 Spectral Dependence on the Extraction Efficiency
3 Stationary Wave Fourier Transform Spectrometry: SWIFTS
3.1 Principal Equations of the SWIFTS Spectrometer
3.2 Dependence of the Signal with the Wavelength and Distance to the Mirror
4 Laser-Written SWIFTS in Passive Materials: Spatial Multiplexing
5 Laser-Written SWIFTS in Active Materials: Temporal Multiplexing
5.1 The Electro-Optic Approach
5.2 Thermo-optic Effect
6 Perspectives: Image Reconstruction, Spectro-Imaging, and Wavefront Sensing
6.1 Arrayed Waveguide Gratings
6.2 Far-Field Spectrometers
6.3 Other Applications: Image Reconstruction, Pupil Remapping, and Wavelength Filtering (Bragg Filters)
References
29 Ultrafast Laser Volume Nanostructuring of Transparent Materials: From Nanophotonics to Nanomechanics
1 Introduction
2 The Laser Process
2.1 Optical Resolution
2.2 Photoinscription Regimes
2.2.1 Positive Refractive Index Changes
2.2.2 Strong Negative Refractive Index Changes
2.2.3 Genesis and Control of Nanogratings
2.2.4 Genesis of Single Nanovoids
2.2.5 Photochemical Transformations
3 Applications of Volume Nanostructures in Optics, Photonics, Micromechanics, and Nanomechanics
3.1 Photonics and Optical Technologies
3.1.1 Multifunctionality: Micro-Optics Fabrication, Nano-Optics, and Nanofluidics
3.1.2 Data Storage and Quantum Technologies
3.1.3 Bragg Waveguide Sensors
3.1.4 Optical Field Readout in Spectro-Imagers: Potential for Astrophotonics
3.2 Nanomechanics
4 Conclusion and Perspectives
References
30 Nanofluidics Fabricated by 3D Femtosecond Laser Processing
1 Introduction
2 Features of Femtosecond Laser Processing for Nanofluidic Fabrication
2.1 Fabrication Resolution Far Beyond Diffraction Limit
2.2 3D Fabrication Capability
3 Methods of Nanofluidic Fabrication by Femtosecond Laser
3.1 Top-Down (Subtractive) Method
3.1.1 Liquid-Assisted Femtosecond Laser Drilling
3.1.2 Femtosecond Laser-Assisted Etching
3.2 Bottom-Up (Additive) Method
4 Applications of Nanofluidics Fabricated by Femtosecond Laser
5 Summary and Outlook
References
31 Laser Structuring for Biomedical Applications
Abbreviations
1 Introduction: Overview on Laser Structuring
1.1 Self-Organization
1.2 Direct Writing
1.3 Non-topographical Modifications
2 Biomedical Applications
2.1 Micro- and Nanostructures for Adhesion, Alignment, and Activation of Cells
2.2 Repellent and Anti-adhesive Structures for Medical Implants and Antimicrobiotic Surfaces
2.3 Cell Arrays and Scaffolds for Tissue Engineering Applications
2.4 Microneedles for Drug/Vaccine Delivery
2.5 Micro- and Nanostructures for Fluidic Systems and Analysis Techniques
2.6 Sensors Based on Micro- and Nanostructures for Biomedical Applications
2.7 Other Applications
3 Summary and Outlook
References
32 Laser Nanostructuring for SERS Applications
1 Introduction
1.1 Overview of SERS Detecting Technologies
1.2 Unique Nanostructures for SERS
1.3 Fabrication Methods for SERS Substrates
2 Overview on Laser Nanostructuring for SERS
3 Laser Nanostructuring of Surfaces for SERS Substrates
3.1 SERS Substrates Fabricated by One-Step Laser Nanostructuring
3.2 SERS Substrates Fabricated by Laser Nanostructuring and Ag/Au Deposition
4 Laser Fabricated Specific Wetting Surfaces for Ultrasensitive SERS Detection via Evaporation Enrichment
4.1 Ultrasensitive SERS Detection with Laser Fabricated Superhydrophobic Surfaces
4.2 Ultrasensitive SERS Detection with Laser Fabricated Patterned Hydrophobic/Superhydrophilic-Superhydrophobic Surfaces
5 Applications of SERS Detection
5.1 SERS for Food Safety Evaluation
5.2 SERS for Cancer Diagnose Detection
5.3 SERS for Other Applications
6 Summary and Perspectives
References
33 Laser Micro- and Nanostructuring for Refractive Eye Surgery
1 Introduction: State of the Art of Femtosecond Laser Refractive Eye Surgery and Concepts for Improvement
1.1 IR fs Laser Refractive Surgery
1.2 Challenges for Precision and Predictability
1.3 Potential Improvements by Focus Shaping, Use of Shorter Wavelengths, and Refractive Index Modifications by Low-Density Plasma
2 Mechanisms of Corneal Dissection
2.1 Modes of Corneal Dissection
2.2 Bubble Dynamics in the Cornea
2.3 Histology: Tissue Bridges and Bubble Content
2.4 Interplay of Consecutive Pulses
3 Focus Shaping by Gaussian and Vortex Beams
3.1 Cutting Precision and Bubble Layer Formed During Dissection
3.2 Improved Cutting Efficiency of Vortex Beams Reduces Mechanical Side Effects
3.3 Improvements of LASIK and SMILE by Focus Shaping
4 Effect of Wavelength and Pulse Duration on Surgical Precision with Gaussian and Vortex Beams
4.1 High Cutting Precision with UV-A Wavelengths
4.2 Pulse Duration Dependence of Cutting Energies for UV and IR Wavelengths
4.3 Safety Considerations
5 Fs Laser-Induced Refractive Index Changes
5.1 Creation of Fresnel Lenses Via Patterned Low-Density Plasma Formation
5.2 Relation of Electron Energy Spectra to the Wavelength Dependence of fs Laser-Induced Refractive Index Changes
6 Conclusion
References