Raped forming of aspherical lenses by laser slicing technology

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14052
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 18020:Manufacturing and production engineering-related
• Research Institution: Saitama University
• Principal Investigator: Yamada Yohei 埼玉大学, 理工学研究科, 助教 (60756899)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: レーザスライシング / 非球面レンズ / 硬脆材料 / レーザ割断 / 精密微細加工

Outline of Final Research Achievements

Laser slicing technology for glass has been facing a problem of processing accuracy due to the lack of control the crack propagation. The visualization of the stress inside glass using FEM and a birefringent stress evaluation system revealed that a residual stress layer, mainly tensile stress, is formed inside the material and that the crack propagates near the laser focus point, where the maximum tensile stress occurs. It was also found that the crack propagation was caused by the formation of a stress concentration at the crack front due to the warping of the glass during crack propagation. Based on this mechanism, laser irradiation conditions were identified and aspherical lens forming was successful.

Free Research Field

レーザ加工

Academic Significance and Societal Importance of the Research Achievements

超短パルスレーザを透明材料内部に集光し、改質により微細なフォトニックデバイスを形成するという研究は国内外問わず盛んに行われているが、材料内部の応力に着目した研究は限られており，この応力を利用して割断加工に応用する研究は，本研究のみである．今回提案したのガラス内部の応力蓄積メカニズムは，学術研究において価値のあるものであると考えている。また，非球面レンズは，AI技術や電気自動車のセンシングに欠かせないものである．熟練の技術を必要とせず，迅速かつ簡便に非球面レンズ成形が可能になる本技術は，社会に貢献できる可能性が大である．