Views
4 years ago

Characterization of the laser induced damage threshold of mirrors in ...

Characterization of the laser induced damage threshold of mirrors in ...

Contents 1 Introduction

Contents 1 Introduction 1 1.1 About the necessity of high damage threshold optics . . . . . . . . . . . . . 1 1.2 Goal of this Thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Thesis outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Femtosecond Damage Threshold 4 2.1 Definition of optical damage, and damage threshold . . . . . . . . . . . . . 4 2.2 Femtosecond laser interaction with dielectrics . . . . . . . . . . . . . . . . 6 2.2.1 Theoretical understanding of fs damage . . . . . . . . . . . . . . . . 6 2.2.2 Mathematical modeling of the fs damage threshold . . . . . . . . . 9 2.3 Dependence of the damage threshold on different parameters . . . . . . . . 13 2.3.1 Dependence on the pulse duration . . . . . . . . . . . . . . . . . . . 13 2.3.2 Pulse frequency dependence . . . . . . . . . . . . . . . . . . . . . . 14 2.3.3 Influence of the center wavelength . . . . . . . . . . . . . . . . . . . 15 2.3.4 Incubation effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2.3.5 Impact of the beam diameter on the damage threshold . . . . . . . 16 2.3.6 Dependence on the band gap . . . . . . . . . . . . . . . . . . . . . 17 2.4 About literature values of damage threshold . . . . . . . . . . . . . . . . . 17 3 Materials and Methods 19 3.1 The laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.1.1 Laser design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.1.2 Laser output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.2 The damage threshold setup . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.2.1 Damage detection principle . . . . . . . . . . . . . . . . . . . . . . 22 3.2.2 Setup design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3.2.3 Focus characterization . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.2.4 Measurement procedure . . . . . . . . . . . . . . . . . . . . . . . . 26 3.2.5 Calibration and measurement . . . . . . . . . . . . . . . . . . . . . 26 3.2.6 Error evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 ii

4 Presentation of Results 31 4.1 Comparative measurement of different mirror types . . . . . . . . . . . . . 31 4.2 Measured damage threshold of fused silica substrate and a gold mirror vs. literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.3 Problems with the measurement . . . . . . . . . . . . . . . . . . . . . . . . 34 5 Conclusion and Outlook 36 5.1 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 5.2 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 5.2.1 Improvement of the setup . . . . . . . . . . . . . . . . . . . . . . . 37 5.2.2 Introducing a model for the better evaluation of the measurement data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 5.2.3 Crosscheck with an established setup and verification of the results 37 5.2.4 Investigations on damage mechanisms and improvement of damage threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 6 Appendix 39 6.1 Appendix A: Derivation of the critical electron density . . . . . . . . . . . 39 6.1.1 The movement of an electron in a solid under the influence of an external electric field . . . . . . . . . . . . . . . . . . . . . . . . . . 39 6.1.2 The dielectric function of a solid including a contribution of free carriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 6.1.3 The plasma frequency and plasma charge density . . . . . . . . . . 40 6.2 Appendix B: Derivation of the evaluation expression . . . . . . . . . . . . . 41 6.2.1 The power measured via the power meter . . . . . . . . . . . . . . . 41 6.2.2 The peak fluence as a function of the time averaged power . . . . . 41 List of References 43 iii

femtosecond laser induced breakdown spectroscopy (LIBS) - CSIR
Laser induced damage - Fusion Energy Research Program - UC ...
Microstructure and laser-induced damage threshold of ZrO2 ...
Effect of laser pulse duration on damage to metal mirrors for laser IFE
Laser Damage Threshold Measurements of Micro-Structure Based High Reflectors
Femtosecond laser-induced damage in dielectrics
Deterministic Nanosecond Laser-Induced Breakdown Thresholds In ...
Laser-induced damage in deuterated potassium ... - mfeit.net
Progress on Laser Induced Damage Studies of Grazing Incidence ...
Characterization techniques for high brightness laser diodes
Single-shot spatially resolved characterization of laser-induced ...
Short and ultrashort laser pulse induced bubbles on - University of ...
Spectroscopic characterization of laser-induced tin plasma
Modeling of Laser Induced Damage in NIF UV Optics
Extracting the distribution of laser damage precursors on ... - mfeit.net
759 ablation threshold, laser wavelength influences on ... - Wiley-VCH
Growth of Laser Initiated Damage in Fused Silica at 1053 ... - mfeit.net
Time-Resolved Studies of Laser-Induced Phase ... - Mazur Group
Molecular dynamics simulations of laser-induced damage of ...
Modeling of Charge Trapping Induced Threshold ... - IEEE Xplore
Growth of Laser Damage in SiO2 under Multiple ... - mfeit.net
Femtosecond Laser Induced Micro-welding of Silver and Copper
Fabrication of Microoptical Elements in Quartz by Laser Induced ...
Temporal and spatial evolution of C2 in laser induced plasma from ...
Invited paper Theory and design of chirped dielectric laser mirrors
Structural modifications in fused silica due to laser damage induced ...
Laser induced microexplosions and applications in laser ...
Analysis of 1w Bulk Laser Damage in KDP - Site Index Page ...
Study of ns and fs pulse laser-induced effects in biological-tissue ...