2023 Fiscal Year Final Research Report
Development of ultra-sensitive multipath laser heterodyne interferometer and evaluation of precursor phenomena ahead of shock wave
| Project/Area Number |
21K18778
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 24:Aerospace engineering, marine and maritime engineering, and related fields
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| Research Institution | Shizuoka University |
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Principal Investigator |
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| Project Period (FY) |
2021-07-09 – 2024-03-31
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| Keywords | マルチパスセル / レーザーヘテロダイン干渉計 / プリカーサー |
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| Outline of Final Research Achievements |
The upper limit of sensitivity enhancement in multipath access was investigated by numerical calculation and experiment. In the calculation of 3.7×1013 ray-trace analysis, the sensitivity enhancement was increased to 5946, whereas the maximum sensitivity enhancement was 1790±160 in the experiment. This difference was determined by the resolution of the optical alignment. Next, the phase stability of the laser interferometer using the multipath cell was evaluated. It was found that the stability decreased with increasing optical path length and was 87.4 deg for an optical path length of 1260 mm. Therefore, it is necessary to reduce the stability by one order of magnitude for the measurement of electron density in the precursor region to prevent interference in the multipath cell by the pulsed beam.
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| Free Research Field |
航空宇宙工学
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| Academic Significance and Societal Importance of the Research Achievements |
マルチパスセルは汎用的な高感度化手法ではあるが感度向上は2桁程度がこれまでの上限であった．我々はミラー及びレーザー光の入射位置，角度を0.001mm，0.001degの精度で網羅的に変化させ，3.7×10^13パターンの光線追跡法により感度向上の上限を検証した．これにより75mmのミラーにより13510倍の感度向上が可能な組み合わせを発見した．また実験により光学系のアライメント分解能により感度上限が決まることを実証した．マルチパスセル自体は汎用的な計測法であり，この成果は多岐にわたる分野で応用可能である．
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