Seiji Katayama received his Ph.D. from Osaka University in 1981. His research interests include laser materials processing. He is Professor Emeritus (Osaka University, Japan) and Senior Executive Fellow, Technology (Nadex Co., Ltd.) & General Manager (Nadex Laser R&D Center; Nadex Products, Co. Ltd.; Tsuruga, Japan). He is the Editor of the book Handbook of Laser Welding Technologies, and one of the authors of New Developments in Advanced Welding and Advances in Laser Materials Processing and has contributed to 30 other books. He has published more than 280 articles in internationally respected journals such as Journal of Laser Applications, Journal of Materials Processing Technology, Materials & Design, Science and Technology of Welding and Joining, and Welding in the World. He has won 20 awards, including the Best Paper Award and the Best Presentation Award, from the Japan Welding Society, Japan Light Metal Welding Association, Laser Institute of America and International Institute of Welding, as well as three prominent awards from the Japanese government (Ministry of Education, Culture, Sports, Science and Technology, and Ministry of Economy, Trade and Industry) and the Japan Science and Technology Agency. He has more than 30 years of teaching experience at Osaka University.