The Pacific-Rim Laser Damage 2015, IV Symposium on Optical Materials for High Power Lasers, co-organized by the American International Society for Optical Engineering (SPIE) and Shanghai Institute of Optics and Fine Mechanics (SIOM), has been held on 17-20 May in Shanghai. The symposium is co-chaired by Prof. Jianda Shao from SIOM, Prof. Takahisa Jitsuno from Osaka University and Prof. Wolfgang Rudolph from University of New Mexico. 91 papers were accepted for presentations, including 53 oral papers and 38 poster papers. The papers are contributed by scientists, engineers and researchers from 13 countries, including USA, United Kingdom, Sweden, Spain, Singapore, Russia, Korea, Japan, Germany, France, Denmark, Australia and China.

The symposium brought together more than 130 scientists, engineers and researchers, including 30 international participants. The symposium is divided into nine main sessions, including High power laser damage, UV through IR; Laser ablation and laser machining; High laser damage resistant coatings; Defects, contamination, polishing, and surface damage; Characterization techniques and measurement protocols; Mechanisms, modeling, and simulations; Nonlinear laser crystals; Laser ceramics; Optical glasses and fibers. No parallel sessions are held this year, allowing the opportunity to discuss common research interests with all the presenters.

The event opened with the symposium welcome given by the Prof. Jianda Shao, who introduced the background, motivation and history of the Pacific Rim Laser Damage, as well as the overview of this symposium on behalf of the program committee. The event's technical talks opened with the plenary talk given by Prof. Hui Zhang from Tsinghua University, China. Two other plenary talks were given by Prof. Yoshiaki Kato from The Graduate School for the Creation of New Photonics Industry (Japan) and Prof. Christoper Wren Carr from Lawrence Livermore National Laboratory (USA), respectively. 19 other well-known experts were invited to report on relevant topics, demonstrating the latest research progress.

On May18 evening, the International Program Committee Members and SPIE representative were invited to attend the round-table discussion. They think that the conference provided an excellent opportunity for world-wide researchers, especially in Pacific Rim, to communicate efficiently, to exchange information on the new problems, solutions, and technologies in the field of laser damage as well as optical materials, and to establish closer collaborations. The Organizing Committee of Pacific Rim Laser Damage will continue to improve this symposium and believe this will contribute to the development of laser technology and laser materials.