Ultra-small mid-infrared spectrometer using highly integrated plasmonic bolometers controlled at constant temperature

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20424
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0302:Electrical and electronic engineering and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Yasunaga Shun 東京大学, 大学院工学系研究科(工学部), 助教 (80963628)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: マイクロボロメータ / 定温制御 / プラズモニクス / 中赤外 / 分光器

Outline of Final Research Achievements

The thermal crosstalk between adjacent bolometers was evaluated using a thermal resistive element array fabricated on silicon. While the crosstalk was observed to decay with distance, the element was maintained at a constant temperature and the crosstalk from adjacent elements cancelled out by appropriately supplementing the heat generated by external electrical energy. A real-time temperature control system was also constructed using a microcomputer and successfully operated.
A fabrication process was then established to build a bolometer device with nanometallic structures with different responses to mid-infrared light, and the optical response of the bolometer arrays was confirmed. Due to process failure, the system could not be directly applied to the aforementioned constant-temperature control system, but we expect that it can be adapted by slightly modifying the system.

Free Research Field

MEMS

Academic Significance and Societal Importance of the Research Achievements

ボロメータはサーモグラフィの形ですでに我々の生活に入り込んでいる身近な技術だが，非シリコン製の受光素子を熱的に基板から隔離し，真空パッケージしなければならないという常識がある．しかし本研究は，そのようにせずとも制御の力を借りてより簡便にボロメータの機能を実現できる可能性を示す点で学術的意義がある．本研究では特に，シリコンベースのボロメータ表面にプラズモニック構造をつくることで中赤外分光器の実現を目指しており，その見通しがたったということは非常に小型で安価な中赤外分光器の実現可能性が高まったということである．人間の目に見えない差を可視化するデバイスの実現で情報化社会の安全性を高める技術となる．