Library of Congress Catalog Card Number: 89-600787 National Institute of Standards and Technology U.S. GOVERNMENT PRINTING OFFICE For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402-9325 Engin 4-26-90 Foreword The Proceedings contain the papers presented at the Twentieth Symposium on Optical Materials for High-Power Lasers held at the National Institute of Standards and Technology in Boulder, Colorado, on October 26-28, 1988. The Symposium was jointly sponsored by the National Institute of Standards and Technology, the American Society for Testing and Materials, the Defense Advanced Research Project Agency, and the Department of Energy. The Symposium was attended by over 210 scientist from the United States, the United Kingdom, France, Canada, People's Republic of China, Japan, the Federal Republic of Germany, Lithuania, and the Soviet Union. It was divided into sessions devoted to the following topics: Materials and Measurements, Mirrors and Surfaces, Thin Films, and finally, Fundamental Mechanisms. The Symposium Co-Chairmen were Dr. Harold E. Bennett of the Naval Weapons Center, Dr. Arthur H. Guenther of the Air Force Weapons Laboratory, Dr. Brian E. Newnam of the Los Alamos National Laboratory, and Dr. M. J. Soileau of the University of Central Florida. They also served as editors of this report. The editors assume full responsibility for the summary article which contains an overview of the Symposium. The manuscripts of the papers presented at the Symposium have been prepared by their authors, and questions pertaining to their content should be addressed to those authors The interested reader is referred to the bibliography at the end of the summary article for general references to the literature of laser damage studies. The Twenty-First Annual Symposium on this topic was held in Boulder, Colorado, November 1-3, 1989. A concerted effort will be made to ensure closer liaison between the practitioners of high-peak power and the high-average power community. The principal topics to be considered as contributed papers in 1989 do not differ drastically from those enumerated above. We expect to hear more about improved scaling relations as a function of pulse duration, area, and wavelength, and to see a continuing transfer of information from research activities to industrial practice. New sources at shorter wavelengths continue to be developed, and a corresponding shift in emphasis to short wavelength and repetitively pulsed damage problems is anticipated, particularly in the RF free-electron laser pulse format. Fabrication and test procedures will continue to be developed, particularly in the thin film areas. New materials, diamond and diamondlike, for example, and the implication of thermal conductivity on damage modelling will undoubtedly be emphasized. The purpose of these symposia is to exchange information about optical materials for high-power lasers. The editors will welcome comment and criticism from all interested readers relevant to this purpose, and particularly relative to our plans for the TwentyFirst Annual Symposium. H. E. Bennett, A.H. Guenther, B. E. Newnam, and M. J. Soileau Disclaimer Certain papers contributed to this publication have been prepared by non-NIST authors. These papers have not been reviewed or edited by NIST; therefore, the National Institute of Standards and Technology accepts no responsibility for comments or recommendations contained therein. Certain commercial equipment, instruments, and materials are identified in this publication in order to explain the experimental procedure adequately. Such identification in no way implies approval, recommendation, or endorsement by the National Institute of Standards and Technology, nor does it imply that the equipment, instruments, or materials identified are necessarily the best available for the purpose. CONTENTS Page FOREWORD H. E. Bennett, A.H. Guenther, B. E. Newnam, and M.J. Soileau iii Laser Heating of Free Electrons and the Mechanism of Intrinsic Laser 49 and Silvinas V. Sakalauskas Repetitively Pulsed Beam Diagnostics for Large Laser Optics Damage D. B. Nichols, D. J. Morris, W. B. Shepherd T. M. Donovan, J. L. Stanford, C. D. Marrs, and C. F. Zahnow |