Vertical External Cavity Surface Emitting Lasers

Michael Jetter is Leader of the Epitaxy and Laser Group, Institute for Semiconductor Optics and Functional Interfaces, University of Stuttgart, Germany. He is expert in III-V semiconductor epitaxy and semiconductor lasers. Peter Michler is Professor and Head of the Institute for Semiconductor Optics and Functional Interfaces, University of Stuttgart, Germany. His research concentrates on quantum dots, non-classical light sources and semiconductor lasers, semiconductor based quantum optics and photonic quantum technologies.

• Preface xiiiPart I Continuous wave VECSEL 11 History of Optically Pumped Semiconductor Lasers – VECSELs 3Mark E. Kuznetsov1.1 Introduction 31.2 OPS-VECSELs: Concept and History 41.3 Micracor 81.4 OPSL Development at Micracor: First Steps 111.5 OPS Development at Micracor: Pushing Forward 141.6 OPS Development at Micracor: Final Chapter 161.7 VECSELs beyond Micracor 20References 222 VECSELs in the Wavelength Range 1.18–1.55 𝛍m 27Antti Rantamäki and Mircea Guina2.1 Introduction 272.2 Overview of GaAs-based Gain Mirror Technologies for Long-wavelength Infrared VECSELs 282.2.1 InGaAs QWs 282.2.2 GaInNAs QWs 282.2.3 InAs QDs 302.2.4 GaAsSb QWs 312.3 Overview of InP-based Gain Mirror Technologies for Long-wavelength Infrared VECSELs 322.3.1 Monolithic InP-based DBRs 322.3.2 Dielectric and Metamorphic DBRs 332.3.3 Semiconductor-dielectric-metal Compound Mirrors 342.3.4 Wafer-bonded GaAs-based DBRs 372.3.4.1 DirectWafer Bonding 392.3.4.2 Low Temperature Bonding 442.3.5 Gain Structures in Transmission 472.4 Conclusion 50References 503 Single-frequency and High Power Operation of 2–3 Micron VECSEL 63Marcel Rattunde, Peter Holl, and Joachim Wagner3.1 Introduction 633.2 Semiconductor Lasers for the MIR Range 643.3 III-Sb Material System 663.4 2–3 μm VECSEL Design 683.4.1 Standard Barrier Pumped Structures 683.4.2 In-well Pumping 693.4.3 Low Quantum Deficit Barrier Pumping 703.5 Mounting Technologies 723.5.1 Intracavity Heatspreader 743.5.2 Thin Device 763.5.3 Double-sided Heatspreader 773.6 Single-frequency Operation (SFO) of 2–3 μm VECSEL 783.6.1 Key Parameters for Single-Frequency Operation 793.6.2 SFO with Intracavity Heatspreader 813.6.2.1 Laser Cavity Setup 823.6.2.2 Wavelength Tuning 833.6.2.3 Emission Linewidth 853.6.2.4 Active Stabilization and Influence of Sampling Time 883.6.2.5 Conclusion 903.6.3 SFO withWedged Heatspreader 913.6.4 SFO with Microcavity VECSELs 923.6.5 SFO without Intracavity Heatspreader 943.7 Conclusion 99References 1014 Highly Coherent Single-Frequency Tunable VeCSELs: Concept, Technology, and Physical Study 109Mikhael Myara4.1 Introduction: Lasers for Applications 1094.2 The “Ideal” Laser 1114.3 Toward Single-Mode Operation 1134.4 Toward High Coherence 1184.5 The VeCSEL in the State of the Art 1214.6 Highly Coherent, Tunable VeCSEL Design 1224.7 Limits and Solutions 1254.8 Highly Coherent, Tunable VeCSEL: Main Characteristics 1274.9 Ultrahigh-Purity Single-mode Operation 1294.10 Spatial Coherence 1314.11 Time Domain Coherence and Noise 1314.11.1 Noise in Photonics: Basics 1314.11.2 Intensity Noise of a VeCSEL 1354.11.3 Phase Noise, Frequency Noise, and Linewidth of a VeCSEL 1364.12 Conclusion 139Acknowledgements 140References 1405 Terahertz Metasurface Quantum Cascade VECSELs 145Benjamin S. Williams and Luyao Xu5.1 Introduction 1455.1.1 Waveguides for THz QC-Lasers 1465.1.2 Overview of Metasurface QC-VECSEL Concept 1485.2 Metasurface Design 1495.3 QC-VECSEL Model 1525.3.1 Confinement Factor 1565.3.2 Metasurface and Cavity Optimization 1575.4 THz QC-VECSEL Performance: Power, Efficiency, and Beam Quality 1595.4.1 Effect of Metasurface on Spectrum 1605.4.2 Effect of Output Coupler 1615.4.3 Focusing Metasurface VECSEL 1625.4.4 Intra-cryostat Cavity QC-VECSEL 1655.5 Polarization Control in QC-VECSELs 1665.6 Conclusion 169References 1706 DBR-free Optically Pumped Semiconductor Disk Lasers 175Alexander R. Albrecht, Zhou Yang, and Mansoor Sheik-Bahae6.1 Introduction 1756.2 DBR-free Semiconductor Disk Lasers 1766.2.1 Opportunities and Advantages 1776.2.2 Thermal Analysis 1786.2.3 Longitudinal Mode Structure and Broadband Tunability 1806.3 Device Fabrication 1826.4 DBR-free SDL Implementation 1856.4.1 High Power Operation 1856.4.2 Broad Tunability 1876.4.3 Wafer-scale Processing 1896.5 Novel Concepts 1896.6 Conclusions 192References 1937 Optically Pumped Red-Emitting AlGaInP-VECSELs and the MECSEL Concept 197Hermann Kahle, Michael Jetter, and Peter Michler7.1 Introduction 1977.2 Direct Red-Emitting AlGaInP-VECSELs and Second-Harmonic Generation 1997.2.1 GaInP QuantumWells and the AlGaInP Material System 1997.2.2 GaInP QuantumWell VECSELs: A Comparison 2017.2.2.1 Architecture of the Semiconductor Structures 2027.2.2.2 Experimental Setup 2037.2.2.3 Characterization Results 2047.2.2.4 Internal Efficiency 2047.2.3 Power Scaling via QuantumWell and Multi-Pass Pumping 2087.2.3.1 QuantumWell Pumping 2087.2.3.2 Multi-Pass Pumping 2107.2.4 Second-Harmonic Generation into the UV-A Spectral Range 2117.3 The Membrane External-Cavity Surface-Emitting Laser (MECSEL) 2127.3.1 The Semiconductor Active Region Membrane 2137.3.2 MECSEL Setup 2157.3.3 MECSEL Characterization 2167.3.3.1 Output Power Measurements 2167.3.3.2 Beam Profile and Beam Quality Factor 2187.3.3.3 Spectra 2187.4 Conclusions 221References 221Part II Mode-Locked VECSEL 2298 Recent Advances in Mode-Locked Vertical-External-Cavity Surface-Emitting Lasers 231Anne C. Tropper8.1 Introduction 2318.1.1 Ultrafast Lasers 2328.1.2 Ultrafast Semiconductor Lasers; Diodes, VECSELs, and MIXSELs 2338.2 Ultrafast Pulse Formation in a Surface-Emitting Semiconductor Laser 2358.2.1 Surface-Emitting Gain Chip Design 2358.2.2 Gain Filtering 2388.2.3 Gain Saturation and Recovery 2398.2.4 Saturable Absorbers for ML-VECSELs and MIXSELs 2418.3 Performance of Passively Mode-Locked Semiconductor Lasers 2448.3.1 Pulse Duration 2448.3.2 Pulse Repetition Rate 2468.3.3 Mode-Locked VECSELs: Visible to Mid-Infrared 2488.3.4 Simulation and Modeling 2498.3.5 Noise 2518.4 Applications 2528.4.1 Biological Imaging 2528.4.2 Quantum Optics 2538.4.3 Supercontinuum Generation and Frequency Combs 2538.4.4 Terahertz Imaging and Spectroscopy 2548.5 Summary and Outlook 255References 2569 Ultrafast Nonequilibrium Carrier Dynamics in Semiconductor Laser Mode-Locking 267I. Kilen, J. Hader, S.W. Koch, and J.V. Moloney9.1 Introduction 2679.2 Background Theory 2699.2.1 Pulse Propagation 2699.2.2 Microscopic Theory 2739.3 Domain Setup/Modeling 2779.3.1 The VECSEL Cavity 2779.3.2 The Gain Region 2789.3.3 The Relaxation Rates and the Round Trip Time 2809.3.4 Noise Buildup to Pulse 2819.4 Numerical Results 2829.4.1 Single-Pass Investigation of QWs and SAMs on the Order of Second Born–Markov Approximation 2829.4.1.1 Inverted QuantumWell 2829.4.1.2 Saturable Absorber 2859.4.2 Mode-Locked VECSELs 2889.4.2.1 Gain, Absorption, and Dispersion 2889.4.2.2 Pulse Buildup and Initial Conditions 2909.4.2.3 Self-Phase Modulation from QWs 2909.4.2.4 Mode-Locked Pulse Family 2919.4.2.5 Influence of Loss on the Mode-Locked Pulse 2949.4.2.6 Limits on the Shortest Possible Pulse and the Hysteresis Effect 2969.5 Outlook 299References 30010 Mode-Locked AlGaInP VECSEL for the Red and UV Spectral Range 305Roman Bek, Michael Jetter, and Peter Michler10.1 Introduction 30510.2 Epitaxial Layer Design of AlGaInP-SESAM Structures 30610.2.1 QuantumWell SESAMs 30610.2.2 Quantum Dot SESAMs 30710.3 Temporal Response of AlGaInP SESAMs 30710.4 Cavity Designs 30910.5 Characterization Methods 31010.6 Mode-Locking Results 31110.6.1 QuantumWell Mode-Locked AlGaInP VECSELs 31110.6.1.1 High Output Power 31110.6.1.2 Femtosecond Operation 31210.6.2 Quantum Dot Mode-Locked AlGaInP VECSELs 31410.7 Second Harmonic Generation into the UV Spectral Range 31510.8 Summary and Outlook 317References 31811 Colliding Pulse Mode-locked VECSEL 321Alexandre Laurain11.1 Introduction 32111.2 Principle of Colliding Pulse Modelocking 32211.3 Requirements for Stable Colliding Pulse Modelocking 32411.3.1 Pulse Timing 32411.3.2 Gain Recovery and Pumping Rate 32411.3.3 Polarization 32611.3.4 ModeWaist and Saturation Fluence 32611.4 Design of an Ultrafast CPM VECSEL 32711.4.1 The Optical Cavity 32711.4.2 The Gain Structure 32811.4.3 The SESAM 33311.5 Modelocking Results 33511.5.1 Robustness of the Modelocking Regime 33511.5.2 Cross Correlation of the Output Beams 33611.5.3 Pulse Duration Optimization 33811.5.4 Multipulse Regime 34011.6 Pulse Interactions in the Saturable Absorber 34111.6.1 Field Intensity Distribution 34111.6.2 Saturable Absorption Model 34311.6.3 Dynamics of the Carrier Density Distribution 34511.6.4 Absorption Losses and Pulse Shaping 34711.6.5 Saturation Fluence of the Absorber 34911.6.6 Power Balance in CPM Operation 35011.7 Summary and Outlook 352Acknowledgments 353References 35312 Self-Mode-Locked Semiconductor Disk Lasers 357Arash Rahimi-Iman12.1 Introduction 35712.2 Mode-Locking Techniques for Optically Pumped SDLs at a Glance 35812.3 History of Saturable-Absorber-Free Pulsed VECSELs 36012.3.1 Self-Mode-Locked Optically Pumped VECSELs 36012.3.1.1 Once Upon a Time – Beyond Magic 36112.3.1.2 Mode Competition – A Struggle for Acceptance 36312.3.1.3 More Than a Flash in the Pan – TriggeredWave of Results 36412.3.2 Harmonic Self-Mode-Locking 36612.3.3 Self-Mode-Locking Quantum-Dot VECSEL 36812.3.4 SML Cavity Configurations 36912.3.5 SML VECSEL at OtherWavelengths 37112.4 Overview on SESAM-Free Mode-Locking Achievements 37312.4.1 Spotlight on SML VECSELs 37312.4.1.1 Pulse Duration 37312.4.1.2 Peak Power 37412.4.1.3 Repetition Rate 37512.4.2 SESAM-Free Alternatives to SML VECSEL 37512.4.2.1 Graphene or Carbon Nanotube Saturable Absorber Mode-Locked VECSELs 37512.4.2.2 SESAM-Free VECSEL Design with Intracavity Kerr Medium 37512.5 Investigations into the Mechanisms and Outlook 37612.5.1 First Studies Concerning the Mechanisms Behind SML 37612.5.2 Z-Scan Measurements of the Nonlinear Refractive Index in a VECSEL Chip 37712.5.3 Applications and Expected Advances 380Acknowledgments 381References 382Index 387