Development of transparent fluoride ceramics that realizes short pulse lasers in the blue-green, green, orange, and red regions

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04926
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 30020:Optical engineering and photon science-related
• Research Institution: Osaka University
• Principal Investigator: Kana Fujioka 大阪大学, レーザー科学研究所, 准教授 (00762395)
• Co-Investigator(Kenkyū-buntansha): 椿本 孝治 大阪大学, レーザー科学研究所, 准教授 (90270579)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 透明セラミックス / 可視域レーザー材料 / プラセオジム / アルカリ土類金属フッ化物 / 濃度消光 / クラスター抑制 / フッ素欠陥 / イオン拡散

Outline of Final Research Achievements

The purpose of this research is to realize transparent ceramics of calcium fluoride and strontium fluoride doped with trivalent Pr ions. The addition of trivalent La ions as the buffer ion was efficient to suppress the fluorescence quenching due to the clustering of Pr ions. The optimum doping density ratio of La to Pr was approximately 5. To reduce the optical scattering and absorption in the sintered ceramics, the oversupply of fluorine was effective in the liquid phase synthesis of the fluoride powder. Based on such knowledge, we have achieved the transparent Pr,La:CaF2 ceramics of which in-line transmission is 86%.

Free Research Field

光学材料

Academic Significance and Societal Importance of the Research Achievements

透光性の高いPr添加セラミックスの製作が可能となり、可視域（波長500 ~ 600 nm）での新しいレーザー材料の可能性を開いた。今後、さらなる透明化が進めば、レーザー微細加工、各種分析、バイオ・医療イメージング、および映像・照明分野への応用が期待できる。分光学的には、Pr添加フッ化物材料に関して、結晶とAlF3系ガラス以外では報告例のない誘導放出断面積をJudd-Ofelt解析によって評価し、AlF3系ガラスに比べて高いことを確認した。