OPPORTUNITIES IN
INTENSE ULTRAFAST
LASERS

Reaching for the Brightest Light

Committee on Opportunities in the Science, Applications, and
Technology of Intense Ultrafast Lasers

Board on Physics and Astronomy

Division on Engineering and Physical Sciences

A Consensus Study Report of

THE NATIONAL ACADEMIES PRESS
Washington, DC
www.nap.edu

THE NATIONAL ACADEMIES PRESS 500 Fifth Street, NW Washington, DC 20001

This study is based on work supported by the Grant No. DE-DC0013488 with the Department of Energy, Grant No. FA9550-14-1-0391 with the Department of the Air Force, and Contract No. N0014-10-G-0589, Task Order #15, with the Department of the Navy. Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any agency or organization that provided support for the project.

International Standard Book Number-13: 978-0-309-46769-8
International Standard Book Number-10: 0-309-46769-1
Digital Object Identifier: https://doi.org/10.17226/24939

Copies of this report are available free of charge from:

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Suggested Citation: National Academies of Sciences, Engineering, and Medicine. 2018. Opportunities in Intense Ultrafast Lasers: Reaching for the Brightest Light. Washington, DC: The National Academies Press. doi: https://doi.org/10.17226/24939.

COMMITTEE ON OPPORTUNITIES IN THE SCIENCE, APPLICATIONS, AND TECHNOLOGY OF INTENSE ULTRAFAST LASERS

PHILIP BUCKSBAUM, NAS,¹ Stanford University, Chair

RICCARDO BETTI, University of Rochester

JOHN COLLIER, Rutherford Appleton Laboratory

LOUIS F. DIMAURO, The Ohio State University

ELSA GARMIRE, NAE,² Dartmouth College

JACQUELINE GISH, NAE, Northrop Grumman Aerospace Systems

ERNIE GLOVER, Gordon and Betty Moore Foundation

MARSHALL JONES, NAE, General Electric Global Research

HENRY C. KAPTEYN, NAS, University of Colorado, Boulder

ANDREW LANKFORD, University of California, Irvine

HOWARD MILCHBERG, University of Maryland

STEPHEN MILTON, Los Alamos National Laboratory

PETER MOULTON, NAE, MIT Lincoln Laboratory

C. KUMAR PATEL, NAS/NAE, Pranalytica, Inc. (resigned September 2016)

Staff

JAMES C. LANCASTER, Director, Board on Physics and Astronomy

DAVID LANG, Senior Program Officer, Board on Physics and Astronomy, Study Director

NEERAJ P. GORKHALY, Associate Program Officer

HENRY KO, Research Assistant, Board on Physics and Astronomy

LINDA WALKER, Program Coordinator, Board on Physics and Astronomy

BETH DOLAN, Financial Associate

__________________

¹ NAS, National Academy of Sciences.

² NAE, National Academy of Engineering.

BOARD ON PHYSICS AND ASTRONOMY

BARBARA V. JACAK, NAS,¹ Lawrence Berkeley National Laboratory, Chair

ABRAHAM LOEB, NAS, Harvard University, Vice Chair

LOUIS F. DIMAURO, Ohio State University

FRANCIS J. DISALVO, NAS, Cornell University

NATHANIEL J. FISCH, Princeton University

DANIEL FISHER, NAS, Stanford University

WENDY FREEDMAN, NAS, University of Chicago

TIM HECKMAN, NAS, Johns Hopkins University

WENDELL T. HILL III, University of Maryland

ALAN J. HURD, Los Alamos National Laboratory

BARBARA JONES, IBM Almaden Research Center

ANDREW J. LANKFORD, University of California, Irvine

NERGIS MAVALVALA, NAS, Massachusetts Institute of Technology

LYMAN A. PAGE, JR., NAS, Princeton University

STEVEN M. RITZ, University of California, Santa Cruz

Staff

JAMES C. LANCASTER, Director

DAVID B. LANG, Senior Program Officer

NEERAJ P. GORKHALY, Associate Program Officer

HENRY KO, Research Assistant

LINDA WALKER, Program Coordinator

BETH DOLAN, Financial Associate

__________________

¹ NAS, National Academy of Sciences.

Preface

The Committee on Opportunities in the Science, Applications, and Technology of Intense Ultrafast Lasers was formed to assess the merit and extent of the scientific and technical advances that such technology would afford the United States were such research pursued in this country.

Specifically, the committee was given the charge reproduced below by the National Academies of Sciences, Engineering, and Medicine.

1. Survey high intensity science and related technology, including the following:
   • Identify science opportunities opened up by ultrafast, high peak power lasers at the frontiers of peak power and average power (“high intensity science”).
   • Assess the potential impact of applications associated with high intensity science.
   • Assess the status of laser engineering and technology in the United States associated with high intensity science.
2. Review the framework in which high intensity science and the development of related technology is conducted in the United States. Such review should take place in an international context, with efforts in Europe to serve as a benchmark. In doing so, the committee is to address the following questions:
   • Is there an explicit or implicit national strategy for stewarding high intensity science in the United States? If not, can one be formulated and if so what would be an appropriate structure for such a strategy?

• Is there a case for a large-scale initiative to coordinate, accelerate, and steward high intensity science at peak and average power well beyond the current state of the art?
• Is there a compelling science case for the construction of a forefront U.S. facility or a staged sequence of facilities in high intensity science at peak powers of 1 petawatt to 1 exawatt? If so, what should the parameters be and what capabilities should be included in such a facility or sequence of facilities?
• Is high peak power laser technology development in the United States being well stewarded? If not, what roadmap should the United States follow for coherently supporting the development of this technology and what new technologies, if any, should be pursued?

The concept for this study was developed by the Committee on Atomic, Molecular, and Optical Sciences (CAMOS), a standing activity of the National Academies that operates under the auspices of the Board on Physics and Astronomy. An important part of CAMOS’s responsibilities is to monitor developments in the atomic, molecular, and optical (AMO) sciences and to develop white papers for potential National Academies’ studies that would address issues arising in that research community. CAMOS began developing this project in 2011 and its principal focus was to help the United States develop its advanced, high-intensity laser science and technology capacities. Those efforts were motivated by three factors: (1) recent breakthroughs in ultrafast high-power lasers and the underlying technology; (2) nearly a decade of community network building in Europe with programs like Laserlab-Europe,¹ Photonics21,² and Horizon 2020,³ taking the advice recommended to U.S. agencies in the 2002 SAUUL report;⁴ and (3) initiation of the first stage of the Extreme Light Infrastructure (ELI) project to build several petawatt facilities at a few key sites in Europe.⁵

Following consultation with the Academies, four agencies agreed to support the study: the Office of Naval Research (ONR), the Air Force Office of Scientific Research (AFOSR), and two Offices of the Department of Energy Office of Science. The Academies worked with these sponsors to develop a statement of task. A study committee of 15 experts in the field was formed to conduct a study responsive to the charge. The committee included experts from universities, national laboratories, small research laser companies, and large companies in the laser industry.

___________________

¹ “LASERLAB-EUROPE,” accessed December 9, 2016, http://www.laserlab-europe.net/.

² “Photonics21,” accessed December 9, 2016, http://www.photonics21.org/.

³ “Horizon 2020 - European Commission,” Horizon 2020, 202, accessed December 9, 2016, https://ec.europa.eu/programmes/horizon2020/.

⁴ P. Bucksbaum, et al., 2002, The Science and Applications of Ultrafast Ultra-intense Lasers.

⁵ “ELI Delivery Consortium | Home,” accessed December 9, 2016, https://eli-laser.eu/.

In response to this charge, the scope of the current report is broader than SAUUL, covering not only the highest-powered lasers but also high-intensity lasers at or just below the petawatt class that can nonetheless create high-intensity environments, often with infrastructure that can be supported by a university or regional center.

To address this task our committee met five times in-person, visited five separate laboratories, and conducted over thirty teleconferences. The first meeting, held in Washington, D.C., allowed the committee to speak directly with representatives of interested government agencies and the Administration. The second meeting was held in Palo Alto, California and featured visits to the SLAC National Accel-

erator Laboratory, Lawrence Berkeley National Laboratory (LBNL), and Lawrence Livermore National Laboratory (LLNL). The third meeting was conducted by a subset of the committee and was held at the ELI-Beamlines site in Dolní Břežany and featured discussions with laboratory personnel, ELI leadership, and European laser science and technology leaders. The fourth meeting, held in Rochester, New York, included a visit to the Laboratory for Laser Energetics (LLE). The fifth and final in-person meeting of the committee was held in Irvine, California, at which the committee focused on coming to consensus on its report. The committee used not only its in-person meetings to gather input, but also organized many teleconferences featuring discussions with experts from universities, laboratories, and industry, both domestic and foreign. Many of these included presentations from scientists, engineers, and laboratory directors engaged in research development of high-intensity lasers and applications in the United States and throughout the world (for example in Figure P.1). The committee also investigated research areas in high-intensity lasers and wrote research summaries. The committee requested input from the community and maintained a website and email for this purpose.

All of these meetings, interactions, discussions, and information-gathering activities, in addition to the knowledge and perspectives of the members themselves, afforded the committee with a broad and comprehensive picture of the state and possible directions of high-intensity, ultrafast laser science and technology in the United States and abroad. With this knowledge we wrote our report and constructed our consensus findings and recommendations. It is the committee’s belief that the agencies and offices identified in this report’s recommendations are best positioned to decide how to effectuate them.

We believe our report provides U.S. policymakers, the community, and industry with the basis from which to build the future development of this strategically important technical area. We anticipate that the historical snapshot of the state of play will also be valuable for future policymakers and program planners.

The committee thanks the many experts with which it conversed and who attended the committee’s meetings, in-person or remotely. The committee is particularly grateful to its gracious hosts at SLAC, LBNL, LLNL, LLE, and ELI-Beamlines. We also thank our sponsors at the Air Force Office of Scientific Research, Department of Energy, and Office of Naval Research for their support of and engagement with this activity.

Acknowledgment of Reviewers

This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

We thank the following individuals for their review of this report:

Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by Thomas Romesser, NAE, Northrop Grumman Aerospace Systems (retired). He was responsible for making certain that an independent examination of this report was carried out in accordance with the standards of

the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.

Contents

SUMMARY

1 INTRODUCTION AND TECHNICAL SUMMARY

1.1 Introduction

1.1.1 Target Readers of This Report

1.1.2 Historical Background for This Study

1.1.3 Extreme Light Infrastructure (ELI)

1.2 Status and Stewardship of High-Intensity Science and Associated Technology in the United States

1.3 High-Intensity Laser Properties

1.4 High-Intensity Laser Technologies

1.5 Limits to Scaling to Still Higher Intensity

1.6 Science and Technology Community

1.7 Science and Applications with High-Intensity Laser Light

1.7.1 High-Density Laser-Plasma Interactions

1.7.2 Connections to Astrophysics

1.7.3 Unique Secondary Sources

1.7.4 Particle Acceleration

1.7.5 Quantum Vacuum Interactions and Non-perturbative Quantum Electrodynamics

1.7.6 Attosecond Science

1.7.7 Commercial Applications for High-Intensity Lasers

2 STEWARDSHIP IN HIGH-INTENSITY LASER SCIENCE AND TECHNOLOGY

2.1 U.S. Leadership in the 20th Century

2.1.1 U.S. Dominated High-Intensity Laser Innovation in the 20th Century

2.1.2 U.S. Commercial Dominance in the 20th Century

2.2 The New Millennium: Transfer of Leadership to Europe

2.2.1 Science and Technology Investment in Lasers Declines in the United States as It Builds Overseas

2.2.2 Changes in the Relative Level of Investment in Laser Science

2.2.3 Transfer of Commercial Leadership to Europe

2.2.4 Start-ups and Mergers in Europe

2.3 Recent Studies Show a Continuing Need for Laser Technology in the 21st Century

2.3.1 Continuing Need for High-Intensity Lasers in the United States

2.3.2 Start-ups in the United States

2.4 Landscape of Past and Present U.S. Agency Stewardship

2.4.1 Historical Trends in Agency Support for High-Intensity Science

2.4.2 Department of Energy

2.4.3 National Science Foundation

2.4.4 Department of Defense

2.5 Commercial Investment and Involvement in High-Intensity Laser Component Development at U.S. Laser Laboratories

2.5.1 Commercial Availability and Key Components Suppliers

2.6 Workforce Development

2.7 European Model for Laser Stewardship

2.7.1 Operations Model for Petawatt Lasers in Extreme Light Infrastructure

2.8 Past U.S. Reports Examining the Prospects of High-Intensity Laser Science

2.8.1 Connecting Quarks with the Cosmos: Eleven Science Questions for the New Century

2.8.2 Frontiers in High Energy Density Physics: The X-Games of Contemporary Science

2.8.3 Science and Applications of Ultrafast Lasers

2.8.4 The Interagency Task Force Report on High Energy Density Physics

3 CURRENT AND FUTURE INTENSE SOURCE TECHNOLOGY

3.1 Current Petawatt-Class Solid-State Lasers and Optical Parametric Chirped-Pulse Amplifiers

3.1.1 Glass-based Systems

3.1.2 Titanium:Sapphire-based Systems

3.1.3 Optical Parametric Chirped-Pulse Amplification-based Systems

3.1.4 State of Current Intense Sources

3.2 Future Intense Source Technology and Systems

3.2.1 Technical Advances

3.2.2 Planned Future Sources

3.2.3 State of Future Intense Source Technology

3.2.4 State of Future Intense Source Systems

3.3 Comparison of High-Intensity Source Technologies

3.3.1 Nd:glass

3.3.2 Ti:sapphire

3.3.3 Optical Parametric Chirped-Pulse Amplification

3.3.4 Yb-doped Bulk Lasers

3.3.5 Yb-doped Fibers

3.3.6 Linac-based Sources (Free-Electron Lasers, Beam-Laser Scattering)

3.3.7 Intensity Considerations

3.4 National Origins of Technology Sources

4 INTERNATIONAL LANDSCAPE

4.1 Introduction

4.2 Global Trends and Distributions

4.3 Extreme Light Infrastructure and Europe

4.4 Petawatt-Class Laser User Community

5 SCIENCE MOTIVATION

5.1 Introduction to the Intensity Roadmap of Opportunities and Discovery

5.2 Ultrafast Spectroscopy and Attosecond Science: The Atomic Unit of Intensity 1-1000 PW/cm²

5.2.1 Extreme Nonlinear Optics: Interrogating the Electrons in Matter

5.2.2 The Attosecond Time Scale in Atoms and Molecules

5.3 High-Intensity Petawatt Laser Studies of High Energy Density Science, Planetary Physics, and Astrophysics

5.3.1 Planetary Physics and Astrophysics

5.3.2 Isochoric Heating and High Energy Density Plasmas

5.3.3 Science That Combines X-ray Free-Electron Lasers, High Energy Electron Accelerators, and Petawatt-Class Lasers

5.4 Petawatt Laser-Driven Particle Accelerators

5.4.1 Particle Acceleration and Particle Physics

5.4.2 Laser-Driven Plasma Wakefield Acceleration

5.5 Intense Laser-Driven Particle Sources of Energetic Photons, Neutrons, and Positrons

5.5.1 Photon Sources

5.5.2 Neutron Sources

5.5.3 Positron Sources

5.6 High-Intensity, Ultrafast Lasers for Nuclear Physics

5.6.1 Introduction

5.6.2 High Power Laser Systems for Nuclear Physics

5.6.3 γ-ray Beam Systems for Nuclear Physics

5.6.4 Applications Beyond Nuclear Physics

5.7 Extreme Intensity: Toward and Beyond the Schwinger Limit of 10¹⁴ PW/cm²

5.7.1 Introduction

5.7.2 The Schwinger Limit

5.7.3 Vacuum Polarization: Matter from Light

5.7.4 Nonlinear Thomson and Compton Scattering

5.7.5 Radiation Reaction

5.7.6 Vacuum Polarization: Elastic Light Scattering

5.7.7 Beyond the Standard Model

6 APPLICATIONS

6.1 Introduction

6.2 Laser Technology Used in Manufacturing

6.3 Applications of High Power (petawatt) Lasers to the Stockpile Stewardship Program

6.4 Applications of High-Intensity Lasers to Medicine

6.4.1 Ultrafast X-ray Radiography in Medicine

6.4.2 Electron Beams for Cancer Therapy

6.4.3 Ion Beams for Cancer Therapy

6.4.4 Laser-Produced Isotopes for Positron Emission Tomography

6.4.5 Future Considerations for Medical Applications

6.5 High Power Lasers Applications: Fusion Energy

6.6 DOD Security Applications

6.6.1 Ultrashort Pulse Applications

6.6.2 Propagation Applications

6.7 Extreme Nonlinear Optics: High-Order Harmonic Generation

6.7.1 The Strong-Field Electron Recollision Process and Its Implications

6.7.2 High-Order Harmonic Generation as a New Coherent Laser Source at Very Short Wavelengths

6.7.3 Technology Needs for Future High-Order Harmonic Generation Research

7 CONCLUSIONS AND RECOMMENDATIONS

7.1 Study Conclusions

7.2 Recommendations

APPENDIXES

A Technical Background Summaries

A1 Technical Terms

A2 Brief History of Laser Technology and the Emergence of Petawatt Laser Technologies

A3 Technologies Beyond Conventional Chirped-Pulse Amplification

A4 Limits to Scaling to Still Higher Peak Powers and Intensities

A5 High-Intensity Laser Acronym List

B Supplemental Information on the Underlying Laser Technology

B1 Basics of Solid-State Lasers

B2 Nonlinear Optics and Optical Parametric Chirped-Pulse Amplification Background

B3 Enabling Technologies

B4 Systems Under Construction or Consideration

C Supplemental Information on the International Community

C1 User Community Search

D Medical Applications of Lasers

D1 Imaging with Hard X-rays

D2 Laser-Accelerated Hadron Beams for Cancer Therapy

D3 Laser-Produced Short-Lived Isotopes for Positron Emission Tomography

E Petawatt-Class Lasers Summary

E1 Nd:Glass Petawatt-Class Lasers

E2 Ti:Sapphire Petawatt-Class Lasers

E3 Optical Parametric Chirped-Pulse Amplification Petawatt-Class Lasers

E4 Diode-pumped Solid-State Petawatt-Class Lasers

F Bibliography of Sources