Elucidation of the mechanism of photodarkening that hinders high output of visible silica fiber lasers

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04658
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Toyota Technological Institute
• Principal Investigator: Saito Kazuya 豊田工業大学, 工学部, 教授 (20278394)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: ファイバレーザー / ファイバアンプ / シリカガラス / フォトダークニング

Outline of Final Research Achievements

The development of a high-power, visible silica fiber laser using a blue LD as an excitation source is highly desirable for processing metals with low infrared absorption, such as copper, which is difficult to process with infrared fiber lasers. However, the practical application of visible silica fiber lasers faces the extremely difficult task of suppressing photodarkening. Photodarkening is a phenomenon in which defects are generated by the excitation laser, and the increased absorption caused by the generated defects inhibits laser oscillation. In this study, we clarified the photodarkening mechanism in Dy-doped silica fiber and identified co-doping agents that are effective in suppressing photodarkening.

Free Research Field

材料工学　無機材料および物性関連

Academic Significance and Societal Importance of the Research Achievements

本研究では、高出力可視加工用レーザーの候補であるDy添加黄色シリカファイバレーザーの実用化に向けた課題解決を行った。具体的にはフォトダークニングの機構解明と抑制法の開発を行った。これらの研究は、欠陥構造の生成機構解明という学術的意義があるにとどまらず、高出力可視ファイバレーザーの実用化に向けた突破口を開くもので、社会的意義も大きい。