Challenges in Non-Contact and Non-Destructive Surface Evaluation Using a Focused Femtosecond Laser Thermal Sensing Probe

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K20953
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 18:Mechanics of materials, production engineering, design engineering, and related fields
• Research Institution: Hokkaido University (2021-2022); Tohoku University (2020)
• Principal Investigator: Shimizu Yuki 北海道大学, 工学研究院, 教授 (70606384)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 熱収支場 / フェムト秒レーザ / 精密位置決め

Outline of Final Research Achievements

The basic principle of a “femtosecond laser thermal sensing probe”, which combines a micro thermal sensor composed of a micro thin-film resistive element and a confocal optical system composed of a focused femtosecond laser, is proposed to achieve both local heating of the sample surface and highly accurate detection of the accompanying micro thermal response. The feasibility of the probe has been experimentally demonstrated by fabricating a micro thermal sensor to be incorporated in the probe, a focused femtosecond laser confocal optics system to detect the gap change when the thermal sensor is placed close to the sample surface, and a femtosecond laser light source.

Free Research Field

生産工学・加工学

Academic Significance and Societal Importance of the Research Achievements

本研究で提案する「フェムト秒レーザ熱検知プローブ」は，マイクロ熱検知素子およびフェムト秒集光レーザプローブをもとに，素子-測定面間に生成した安定熱収支場を生成し，測定試料面の性状変化に伴う熱的平衡状態の変化を，センサ出力変化を通じて検知することを試みるものである．今回の検討により，フェムト秒集光レーザプローブと熱検知センサとの高精度位置合わせ実現の可能性が見いだせたこと，およびセンサと測定面との近接状態変化を検出できる可能性が見いだせた．「熱」を積極的に精密計測に援用する本手法をさらに発展させると，学術的にもより意義があるものになると期待される．