YASUHIRO OKAMOTO

Last Updated :2025/06/26

Affiliations, Positions
Graduate School of Advanced Science and Engineering, Professor
E-mail
okahirohiroshima-u.ac.jp
Self-introduction
I am mainly conducting education and research works of laser material processing by the collaboration with companies and researchers both in Japan and overseas through various academic societies, for opening advanced production processes using high energy beam.

Basic Information

Educational Backgrounds

  • Okayama University, Graduate School of Engineering, Division of Mechanical Engineering, 1996/04, 1998/03
  • Okayama University, Faculty of Engineering, Department of Mechanical Engineering, 1992/04, 1996/03

Academic Degrees

  • Doctor of Engineering, The University of Osaka

In Charge of Primary Major Programs

  • Program of Material Processing

Research Fields

  • Engineering;Mechanical engineering;Production engineering / Processing studies
  • Engineering;Mechanical engineering;Materials / Mechanics of materials

Research Keywords

  • Laser Beam Machining
  • Material Processing
  • Electrical Discharge Machiring

Affiliated Academic Societies

  • Japan Welding Society
  • Smart Processing Society for Materials, Environment & Energy
  • Japan Society of Mechanical Engineers
  • Japan Society of Electrical-Machining Engineers
  • Laser Institute of America
  • The Laser Society of Japan
  • LASER PLATFORM ASSOCIATION
  • The Japan Society for Precision Engineering
  • Japan Laser Processing Society

Educational Activity

Course in Charge

  1. 2025, Liberal Arts Education Program1, 1Term, Introductory Seminar for First-Year Students
  2. 2025, Liberal Arts Education Program1, 1Term, Introductory Seminar for First-Year Students
  3. 2025, Undergraduate Education, 1Term, An Introduction to Engineering Materials
  4. 2025, Undergraduate Education, 4Term, Mechanical Materials II
  5. 2025, Graduate Education (Master's Program) , 3Term, Advanced in Composite Science and Engineering

Research Activities

Academic Papers

  1. Direct welding of silicon carbide and fused silica using femtosecond lasers: Effects of repetition rate and focal depth, Optics & Laser Technology, 184, 112489-112489, 202506
  2. Fundamental Study on Influence of Residual Stress Distribution on Fatigue Strength in ns Pulsed Laser Peening for Welded High-Strength Steel, Defect and Diffusion Forum, 441, 61-68, 20250326
  3. ★, High-quality welding of copper and aluminum by angled laser irradiation and insert metals, Journal of Laser Applications, 37(1), 12041:1-12041:8, 20250201
  4. A Comparison of Weldability and Mechanical Properties of Additive Manufactured and Bulk Ti6Al4V Alloy, Materials Design and Applications V. Advanced Structured Materials, 212, 69-79, 20241109
  5. Fundamental Study on Calcination of Limestone Particles by Near-infrared Wavelength Laser with Vibration Stirring, Proceedings of ICPE2024, Os10-11, 202410
  6. Investigation of Effective Gas Shielding Method for a Wide-area in Vertical-position Laser Welding of Titanium, International Journal of Electrical Machining, 20-29, 202403
  7. Application of large-area electron beam irradiation to micro-edge filleting, Journal of Manufacturing Processes, 107, 65-73, 202312
  8. ★, Fiber laser cutting of steel plate by twin spot beam setting in scanning direction, Journal of Laser Applications, 35(4), 042049:1-042049:11, 20231018
  9. Fundamental study on high-quality welding of copper and aluminum by angled and superposed irradiation of blue and near-infrared lasers, Journal of Laser Applications, 35(4), 042005:1-042005:9, 20230906
  10. ★, Study on joint characteristics in laser butt welding of AMed and wrought Ti6Al4V plates, Welding in the World, 67(5), 1997-2005, 20230608
  11. Effect of scanning speed on molten metal behaviour under angled irradiation with a continuous-wave laser, Journal of Materials Processing Technology, 313, 117866-117866, 202304
  12. Fiber laser cutting of steel materials with twin spot beam-twin spot setting in kerf width direction, Journal of Laser Applications, 34, 042009-1-042009-7, 202209
  13. ★, High-quality Micro-shape Fabrication of Monocrystalline Diamond by Nanosecond Pulsed Laser and Acid Cleaning, International Journal of Extreme Manufacturing, 025301, 20220317
  14. Joint integrity evaluation of laser beam welded additive manufactured Ti6Al4V sheets, Scientific Reports, 12(12), 4602, 20220308
  15. Study on Laser Drilling Process of Solid Metal on Its Liquid, International Journal of Electrical Machining, 27, 35-39, 202203
  16. ★, Effects of superposition of 532 nm and 1064 nm wavelengths in copper micro-welding by pulsed Nd:YAG laser, Journal of Materials Processing Technology, 299, 117388-117388, 202201
  17. Formation and Its Mechanism of High-speed Micro-grooving on Metal Surface by Angled CW Laser Irradiation, Journal of Laser Micro/Nanoengineering, 16(2), 109-114, 202110
  18. Investigation and optimization of heat treatment process on tensile behaviour of Ti6Al4V alloy, Materialwissenschaft und Werkstofftechnik, 52(10), 1057-1063, 202110
  19. Laser Butt Welding of Thin Ti6Al4V Sheets: Effects of Welding Parameters, Journal of Composites Science, 5(9), 246-246, 20210914
  20. Influence of Free-electron Density Distribution on Mechanical Strength in Micro-welding of Glass by Picosecond Pulsed Laser, Journal of Smart Processing, 10(5), 294-300, 202109
  21. Investigation on reduction of dross height by analyzing beam intensity distribution in fiber laser cutting, Journal of Laser Applications, 33(4), 109-114, 202109
  22. Surface smoothing and repairing of additively manufactured metal products by large-area electron beam irradiation, CIRP Annals, 70(1), 143-146, 20210513
  23. Reliable and strong micro-welding of glass by ultrashort pulsed laser, Proceedings of SPIE, 11676, 116760P-1-116760P-7, 20210305
  24. Surface Profile Variation of Periodic Surface Nanostructures Produced by Ultrashort Pulsed Laser for Enhancement of Cell Orientation, International Journal of Electrical Machining, 26, 54-54, 202103
  25. Fundamental study on reduction of dross in fiber laser cutting of steel by shifting nozzle axis, Journal of Laser Applications, 33(1), 012022-012022, 202102
  26. High-Speed Micro-Grooving of Metal by Angled Irradiation of Single-Mode CW Fiber Laser, Applied Sciences, 10(23), 8333-1-8333-11, 20201124
  27. Effect of numerical aperture on molten area characteristics in micro-joining of glass by picosecond pulsed laser, Welding in the World, 64(6), 937-947, 202006
  28. Investigation on Surface Smoothing of Mold Material by Pulsed Laser Irradiation of 532 nm, Procedia CIRP, 95, 879-884, 202002
  29. Clarification of Temperature Distribution for Metals with Different Thermal Conductivity in Large-area Electron Beam Irradiation, Procedia CIRP, 95, 960-965, 202002
  30. High surface quality micro machining of monocrystalline diamond by picosecond pulsed laser, CIRP ANNALS-MANUFACTURING TECHNOLOGY, 68(1), 197-200, 201908
  31. Influence of Numerical Aperture on Molten Area Formation in Fusion Micro-Welding of Glass by Picosecond Pulsed Laser, APPLIED SCIENCES-BASEL, 9(7), 20190401
  32. Investigation of Separation Method for Gallium Nitride with Internal Modified Layer by Ultrashort Pulsed Laser, International Journal of Electrical Machining, 24, 21-26, 201903
  33. Influence of Surface State in Micro-Welding of Copper by Nd:YAG Laser, APPLIED SCIENCES-BASEL, 8(12), 201812
  34. Effects of polarization direction on removal characteristics of silver nanowire transparent conductive film by ultrashort pulsed laser, JOURNAL OF ADVANCED MECHANICAL DESIGN SYSTEMS AND MANUFACTURING, 12(5), JAMDSM0100-JAMDSM0100, 201810
  35. ★, High surface quality welding of aluminum using adjustable ring-mode fiber laser, Journal of Materials Processing Technology, 258(8), 180-188, 20180801
  36. Influence of Pulse Duration on Effective Energy on Material Removal in Micro-processing of Mild Steel by Several Hundred Nanoseconds Pulsed Laser, International Journal of Electrical Machining, 23, 38-44, 201803
  37. Study on Reduction of Discoloration Area in Micro-drilling of Multi-layered Artificial Skin by Picosecond Pulsed Laser, International Journal of Electrical Machining, 22(22), 8-13, 20170301
  38. Investigation on Visibility of Drilled Hole in Laser Micro-drilling of Multi-layered Artificial Skin, International Journal of Electrical Machining, 21(21), 13-17, 20160301
  39. Effect of Laser Beam Intensity Distribution in Removal Processing of ZnO Film by ns Pulsed Fiber Laser of Square Core, Journal of the Japan Society for Precision Engineering, 81(11), 1033-1038, 20151101
  40. Effect of Tilting Jet Flushing Nozzle on Wire EDM Performance, International Journal of Electrical Machining, 20(20), 2-8, 20150301
  41. Influence of Bead Geometry on Weld Distortion in Laser Micro-welding of Thin Stainless Steel Sheet with High-speed Scanning, International Journal of Electrical Machining, 20(20), 9-15, 20150301
  42. The Boundary of Key-hole Generation in Micro-welding of Aluminum Alloy by Pulsed Nd:YAG Laser with Superposition of Continuous Diode Laser, Journal of Japanese Society for Precision Engineering, 80(4), 419-424, 20140401
  43. Study on Possibility of Micro-deburring by Large-area Electron Beam Irradiation, International Journal of Electrical Machining, 19(19), 22-27, 2014
  44. Singulation Characteristics of Semiconductor Package Using Pulsed Fiber Laser and SHG:YAG Laser, International Journal of Electrical Machining, 19(19), 28-33, 2014

Publications such as books

  1. 2012, Nd YAG Laser "jointly worked", Nd YAG Laser "jointly worked", Scholarly Book, Joint work, eng

Invited Lecture, Oral Presentation, Poster Presentation

  1. Micro-welding of glass by multi-spot beam of picosecond pulsed laser, Yasuhiro Okamoto, 2025 Shanghai International Forum on Innovative Laser Application, 2025/03/09, With Invitation, English, Shanghai
  2. Reliable micro-welding of glass by picosecond pulsed laser with high pulse repetition rate, Yasuhiro Okamoto, Conference on Frontiers of Extreme Manufacturing, 2025/04/26, With Invitation, English, Ningbo, China
  3. Recent topics of laser applications in Japan and impact of beam intensity control and irradiation method, Yasuhiro Okamoto, 13th CIRP Conference on Photonic Technologies LANE2024, 2024/09/16, With Invitation, English, Bayerisches Laserzentrum GmbH, Fürth
  4. Micro-structuring Characteristics on Metal Surface by High-speed Scanning of Angled CW Laser Irradiation, Taiki Kawai, Riku Saitou; Atsuhiko Sakai; Yasuhiro Okamoto; Togo Shinonaga; Akira Okada, 25th International Symposium on Laser Precision Microfabrication – LPM2024, 2024/06/14, Without Invitation, English
  5. History of LPM, Yasuhiro Okamoto, 25th International Symposium on Laser Precision Microfabrication – LPM2024, 2024/06/11, With Invitation, English
  6. Stabilizing the absorption of laser energy in welding of copper, Yasuhiro Okamoto, 15th International Conference on Materials Processing and Characterization (ICMPC), 2023/09/06, Without Invitation, English, Newcastel
  7. Investigation on high-quality laser welding of copper and aluminum, Yasuhiro Okamoto, Yuki Yamada; Akihiro Ochi; Akira Okada; Takeshi Yamamura; Katsutoshi Nagasaki; Kazunobu Mameno; Norio Nishi, International Conference on Processing & Manufacuturing of Advanced Materials (THERMEC2023), 2023/07/04, With Invitation, English, Wein
  8. Investigation on Laser Welding of Copper and Aluminum by Irradiation from Copper-side, Yasuhiro Okamoto; Yuki Yamada; Akihiro Ochi; Takeshi Yamamura; Katsutoshi Nagasaki; Kazunobu Mameno; Norio Nishi; Akira Okada, Laser in Manufacturing 2023, 2023/06/28, With Invitation, English, WLT, Munich
  9. Recent topics of laser applications in Japan and high-quality Cu/Al laser welding, Yasuhiro Okamoto, 8th Industrial Laser Applications Symposium, ILAS 2023, 2023/03/22, With Invitation, English, AILU, Daventry, UK
  10. Stabilization of Fusion Micro-welding of Glass by Picosecond Pulsed Laser, Yasuhiro Okamoto, Yuta Ogino, Togo Shinonaga, Akira Okada, International Conference on Processing and Manufacturing of Advanced Materials (THERMEC '2018), 2018/07, With Invitation, English
  11. Basics and Advanced Applications of Laser Material Processing, Yasuhiro Okamoto, Special Open Seminar, African Union -african innovation - JKUAT AND PAUSTI Network Project, 2018/05, With Invitation, English
  12. Thought of Future Manufacturing (MONOZUKURI) -Laser Beam Processing-, Yasuhiro Okamoto, 2018 Sustainable Research and Innovation Conference, 2018/05, With Invitation, English

Awards

  1. 2024/09, Best Paper Award, The 5th International Conference on Machining, Material and Mechanical Technologies (IC3MT 2024)
  2. 2024/07, Best Author Award, International Journal of Extreme Manufacturing

Patented

  1. Patent, US11890691B2, 2024/02/26, Wire electric discharge machining device, and control method and control program therefor
  2. Patent, EP2674239B1, 2020/12/16, Laser Processing Method
  3. Patent, US9364910B2, 2016/08/22, Wire electrical discharge machining system, wire electrical discharge machining method, and workpiece
  4. Patent, US 9,375,799 B2, 2016/06/28, Multi-wire electrical discharge machining system, multi-wire electrical discharge machining apparatus, power supply device, multi-wire electrical discharge machining method, semiconductor substrate, solar cell substrate, substrate manufacturing system, and substrate manufacturing method
  5. Patent, US 8,933,367 B2, 2015/01/13, LASER PROCESSING METHOD

External Funds

Acceptance Results of Competitive Funds

  1. Grants-in-Aid for Scientific Research, Study on Improvement in Wire Electrical Discharge Machining Performance by Optimizing Flow of Dielectric Working Fluid, 2024/04/01, 2028/03/31
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  2. Grants-in-Aid for Scientific Research, Highly Efficient Surface Smoothing of AMed Metal Products by EB Polishing, 2024/04/01, 2027/03/31
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  3. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), High-reliable and high-quality welding of Cu and Al by superposition of angled near-infrared laser and elliptic blue laser, 2021/04, 2025/03
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  4. 2023/04, 2024/03
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  5. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Highly Efficient Surface Smoothing by Clarification of EB Polishing Mechanism with Considering Flow of Material, 2021/04, 2024/03
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  6. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Study on Formation of High-performance Metal Mold Surface by EDM with Hybrid Metal Powder Mixed Fluid, 2020/04, 2024/03
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  7. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), 2019/04, 2023/03
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  8. 2019/04, 2021/03
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  9. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), High quality laser processing with low visibility for flexible film with transparent conductive layer, 2018/04, 2021/03
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  10. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Study on High-performance Surface Finishing by Large-area Electron Beam Irradiation, 2016/04, 2019/03
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  11. 2018/04, 2019/02
  12. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Development of High-quality and High-reliable Laser Micro-welding of Difficult-to-weld Materials, 2015/04, 2018/03
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  13. Grants-in-Aid for Scientific Research, High Efficient Surface Finishing of Sintered Hard Materials for Metal Mold by Large-area Electron Beam Irradiation, 2012/04/01, 2015/03/31
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  14. Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Direct bonding of semiconductor material and glass by ultra-short pulsed laser, 2012/04, 2015/03
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  15. Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Development of Micro-welding by Ultra-short Pulsed Laser to Perform High-quality Joint of Glass, 2009, 2011
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  16. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Study on Surface Finishing and Surface Modification of Metal Mold by Large-area Short-pulse Electron Beam, 2008, 2010
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  17. Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Fine Laser Cutting of Thin Plate by High-performance Nozzle for Molten Material, 2007, 2008
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  18. Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), 2005, 2007
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  19. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), DEVELOPMENT OF HIGH EFFICIENCY SURFACE TREATMENT OF METAL MOLD BYLARGE-AREAELECTRON BEAM IRRADIATION, 2005, 2007
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  20. Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), 2002, 2004
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  21. Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), High Efficiency and High Accuracy Multi-wire EDM Slicing Method of Monocrystalline Silicon Ingot, 2002, 2004
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  22. Grants-in-Aid for Scientific Research Grant-in-Aid for Encouragement of Young Scientists (A), 2000, 2001
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  23. Grants-in-Aid for Scientific Research Grant-in-Aid for Exploratory Research, 1999, 2001
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Social Activities

History as Committee Members

  1. Vice President, 2020/06, Japan Laser Processing Society
  2. Board member, 2014, LASER PLATFORM ASSOCIATION
  3. Senior Editor, Journal of Laser Applications, 2020/04, Laser Institute of America
  4. Board member, Chugoku-Shikoku branch, 2020/02, The Japan Society for Precision Engineering
  5. Editor, Journal of Laser Micro / Nanoengineering, 2017/04, Japan Laser Processing Society
  6. Board member, Chugoku branch, 2016/04, Japan Welding Society
  7. Board member, 2016/04, Assicuation for Advanced Machining Technologies
  8. Board member, 2007/04, 2020/05, Japan Laser Processing Society

Organizing Academic Conferences, etc.

  1. The 25th International Symposium on Laser Precision Microfabrication, LPM2024, Ggeneral chair, 2023/06, 2024/06
  2. The 9th International Congress on Laser Advanced Materials Processing LAMP2025, Ggeneral chair, 2024/06, 2025/06
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History as Peer Reviews of Academic Papers

  1. 2020, Precision Engineering, Others, Reviewer, 2
  2. 2023, Journal of Materials Processing Technology, Others, Reviewer, 1
  3. 2022, Materials_Science, Others, Reviewer, 1
  4. 2021, Mechanical Engineering Letters, Others, Reviewer, 2
  5. 2020, International Journal of Automation Technology, Others, Reviewer, 1
  6. 2024, Optics and Laser Technology, Others, Reviewer, 1
  7. 2022, Optics and Laser Technology, Others, Reviewer, 2
  8. 2024, Journal of Laser Applications, Others, Reivewer, 1
  9. 2023, Journal of Laser Applications, Others, Reivewer, 3
  10. 2022, Journal of Laser Applications, Others, Reviewer, 1
  11. 2021, Journal of Laser Applications, Others, Reviewer, 1
  12. 2020, Journal of Laser Applications, Others, Reivewer, 1