| 研究課題/領域番号 |
20H02197
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| 研究機関 | 東京大学 |
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研究代表者 |
何 亜倫 東京大学, 大学院工学系研究科(工学部), 助教 (20815386)
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| 研究分担者 |
項 栄 東京大学, 大学院工学系研究科(工学部), 外国人客員研究員 (20740096)
八井 崇 豊橋技術科学大学, 工学(系)研究科(研究院), 教授 (80505248)
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| 研究期間 (年度) |
2020-04-01 – 2023-03-31
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| キーワード | ナノレーザー / ペロブスカイトナノ結晶 / コロイド量子ドット / プラズモニクス |
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| 研究実績の概要 |
This year, we propose and develop a lithographic in-mold patterning method, which utilizes nanocrystal(colloidal quantum dot) concentration control and a multi-step filling-drying process to achieve CsPbBr3 nanocrystal distributed-Bragg-reflector (DBR) waveguide lasers.
Lead halide perovskites have emerged as promising gain mediums for laser applications. However, their fragile nature poses a challenge for fabricating small-size, low-roughness, and single-mode lasers using conventional lithography and etching techniques. The proposed method provides a promising method to overcome this limitation.
The proposed method also enables the fabrication of compact arrays of DBR lasers, which is crucial for integrating perovskite-based lasers into complex optoelectronic circuits. Overall, this novel lithographic in-mold patterning method shows great potential for realizing high-performance perovskite-based lasers with enhanced stability and reliability.
Furthermore, since plasmonic nanolasers provide a valuable opportunity for expanding subwavelength applications, we also demonstrate metallic nanowire (NW) coupled CsPbBr3 quantum dots (QDs) plasmonic-waveguide lasers this year.
The demonstration of this metallic NW coupled QDs plasmonic nanolaser represents an alternative approach for ultrasmall light sources and offers insights for fundamental studies of light-matter interactions.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
1: 当初の計画以上に進展している
理由
By patterning the CsPbBr3 nanocrystal laser cavity and DBR grating without lift-off and etching processes, the proposed method achieves the smallest fabricated structures in the range of a few hundred nanometers. The single-mode lasing is demonstrated at room temperature with a low threshold of 23.5 μJ cm－2 and a narrowest full width at half maximum (FWHM) of 0.4 nm.
For the plasmonic laser work, by embedding Ag NWs in the QD film, an evolution from amplified spontaneous emission to localized surface plasmon resonance (LSPR) supported random lasing is observed, with a FWHM of 6.6 nm.
Moreover, by focusing the pump light on a single Ag NW, a QD-NW coupled plasmonic-waveguide laser with a significantly narrower emission peak (FWHM = 0.4 nm) is realized, facilitated by a uniform polyvinylpyrrolidone layer. In this configuration, the QDs act as the gain medium while the Ag NW serves as a resonant cavity and propagating plasmonic lasing modes. In addition to the demonstration of a plasmonic single-mode laser, the pumping of two Ag NWs with different directions enables the realization of a dual-wavelength lasing switch.
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| 今後の研究の推進方策 |
To integrate perovskite small lasers for further nanophotonic applications, the on-chip top-down fabrication process for perovskite lasers is desired as mentioned and the large area, size-controllable, and well-alignment perovskite lasers were thus demonstrated. Due to the development of the top-down process for the perovskites, the coupling between a perovskite laser cavity and a waveguide can be demonstrated.
Based on the progress on top-down fabricated perovskite nanocrystal/quantum-dot lasers, we will further demonstrate the coupling of laser and waveguide. Also, the top-down fabricated perovskite laser based on subwavelength plasmonic laser will be investigated.
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