Faculty of Science and Technology
Profile Information
- Affiliation
- Professor, Graduate School of Science and Technology, Master's (Doctoral) Program in Science and Technology, Sophia University
- Degree
- 博士（工学）(東京大学)
- Contact information
- k-ema
sophia.ac.jp - Researcher number
- 40194021
- J-GLOBAL ID
- 200901045168026490
- researchmap Member ID
- 1000167951
1983-1986 Mechanical properties of optical glass fibers
1986-1991 Pulse-shape control of ultrafast optical pulses
1991-2002 Pulse propagation properties in excitonic resonant region
1991-present Nonlinear optics at exciton resonance in semiconductors
1994-present Generation and control of coherent phonons in semiconductors
1995-2001 Optical properties and nonlinear optics in polymers
1996-present Optical properties in organic-inorganic hybrid materials
2004-present Optical properties of photo-catalysis materials
2006-present Optical properties of semiconductor nanocolumns
2006-2010 Optical properties and nonlinear optics in a quantum-dot ensemble
2006-present Anderson localization of light and random lasing
2007-present Optical properties of nitride semiconductors
I study optical properties in semiconductors and organic materials by means of time-resolved and/or nonlinear spectroscopy with ultrafast optical pulses. Recently I mainly study optical properties of semiconductor nanostructures. For a carrier in education, I have been teaching lectures concerning optics and optical physics for more than ten years, such as “Electromagnetics II”, “Optical physics”, “Quantum optics”, and “Optical properties in solids”. Also I have been teaching a general educational lecture named “Physics in daily life” for more than ten years.
(Subject of research)
Ultrafast Optical Signal Processing
Excitonic Nonlinear Optics
Optical properties of inorganic-organic materials
Optical properties of Photocatalytic materials
Optical properties of semiconductor nanostructure
Light loclization and random lasing
Research Interests
13Research Areas
4Research History
13-
Apr, 2001 - Present
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Apr, 2017 - Mar, 2021
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Apr, 2012 - Mar, 2014
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Jun, 2005 - May, 2011
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May, 2008 - Mar, 2010
Education
3-
Apr, 1985 - Oct, 1986
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Apr, 1983 - Mar, 1985
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Apr, 1979 - Mar, 1983
Committee Memberships
17-
Apr, 2022 - Present
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Apr, 2020 - Present
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Apr, 2017 - Present
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Apr, 2015 - Present
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Apr, 2001 - Present
Awards
1-
1992
Papers
209-
The Journal of Chemical Physics, 161(17), Nov 1, 2024 Peer-reviewedLast authorCorresponding authorMetal halide perovskite materials (MHPs) are promising for several applications due to their exceptional properties. Understanding excitonic properties is essential for exploiting these materials. For this purpose, we focus on CsPbBr3 single crystals, which have higher crystal quality, are more stable, and have no Rashba effect at low temperatures compared to other 3D MHPs. We have estimated exciton energy positions, longitudinal-transverse splitting energy, and damping energy using low-temperature reflection spectra. Under high excitation intensity, two biexciton emissions (M-emission) and exciton–exciton scattering emission (P-emission) were observed. We assign the two M-emissions to the emission to the states of longitudinal and transverse excitons, i.e., ML and MT emissions. From the energy position of the MT emission, the biexciton binding energy has been estimated to be ∼2 meV. By analyzing P-emission obtained from the back side of the sample, we have estimated the exciton binding energy to be 17.8–23.7 meV. This estimation minimizes the influence of the wavenumber distribution in the scattering process. In addition, time-resolved transmittance measurements using pulsed white light have revealed the group velocity dispersion. Comparing experimental results with theoretical calculations using the Lorentz model clarifies that exciton dynamics in CsPbBr3 can be described with a simple Lorentz model. These insights enhance the understanding of exciton behavior and support the development of exciton-based devices using MHPs.
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Analytical Sciences, Nov 27, 2022 Peer-reviewedLast authorCorresponding author
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Journal of Applied Physics, 130(14), Oct 14, 2021 Peer-reviewedLast authorCorresponding author
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J. Appl. Phys., 128(13) 133102-1-133102-10, Oct 1, 2020 Peer-reviewedLast authorCorresponding author
Misc.
163-
応用物理学会秋季学術講演会講演予稿集(CD-ROM), 84th, 2023
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応用物理学会秋季学術講演会講演予稿集(CD-ROM), 84th, 2023
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応用物理学会春季学術講演会講演予稿集(CD-ROM), 70th, 2023
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応用物理学会春季学術講演会講演予稿集(CD-ROM), 69th, 2022
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応用物理学会春季学術講演会講演予稿集(CD-ROM), 68th, 2021
Books and Other Publications
31Presentations
84-
Sophia Open Research Week 2023 講演会「光を用いた高機能細菌検出－その基本原理と実例－」、上智大学, Nov 18, 2023 Invited
Professional Memberships
4Research Projects
37-
Grants-in-Aid for Scientific Research, Japan Society for the Promotion of Science, Apr, 2024 - Mar, 2028
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科学研究費助成事業, 日本学術振興会, Apr, 2024 - Mar, 2027
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Sophia University Special Grant for Academic Research “Research in Priority Areas”, Sophia University, Aug, 2021 - Mar, 2024
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Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory), Japan Society for the Promotion of Science, Jun, 2017 - Mar, 2020
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Japan Society for the Promotion of Science, Apr, 2016 - Mar, 2020
Industrial Property Rights
3Other
3-
1998文化系学生向けに，物理の考え方と面白さを，身近な題材を用いて講義している．90分の講義を3テーマくらいに分けて，30分程度で一つの話題に時間を抑えている．これは，もし興味の沸かないテーマだった場合にも切り替えが速いことで対応できること，および興味が沸いた学生にとっては，もっと深く知りたいと感じたところで終わり，自分で調べる意欲を沸かせるという教育上の効果を狙っている．
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1994すべての講義において，自作の補助教材を用意し，事前に学生に配布している．図表や細かい式などは，その教材に記載されているので，学生は講義の最中に長い式や複雑な図表のノート取りの必要はなく，講義の内容を聞くことに集中できる．また，動画を見た方がわかりやすいものは，ノートＰＣを使って動画を見せたり，わかりやすいスライドを見せることも行っている．