| 研究課題/領域番号 |
19K15052
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| 研究機関 | 国立研究開発法人理化学研究所 |
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研究代表者 |
王 利 国立研究開発法人理化学研究所, 光量子工学研究センター, 特別研究員 (50804035)
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| 研究期間 (年度) |
2019-04-01 – 2021-03-31
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| キーワード | THz-QCL / 1.8THz |
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| 研究実績の概要 |
1. more efficient and more reliable simulation package based on non-equilibrium Green's function has been achieved: first, the whole simulation package is set working at parallel computing mode, making to obtain the optical gain in less than 2 hours; second, scattering rate between the basic laser quantum states is resulted, it is very useful to understand the lasing process in new design structures; third, assisted-scattering scheme based on four-wells is predicted in which the optical gain can reach up 40/cm at 230K. 2. high crystal growth of superlattice GaAs/Al0.2Ga0.8As with each layer thickness less than 1% fluctuation is realized, in addition, more reliable processing of Au-Au metals waveguides is done. lasing of 1.8THz at 170K is achieved at present.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
1. the target for improving the simulation package is realized: the computing mode is transferred to parallel and also the electron-electron interactions for scattering effect on the optical gain is modeled, resulting in the calculation more reliable;
2. the initial lasing devices are realized, based on those results, the further optimization direction is clarified.
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| 今後の研究の推進方策 |
the main plan is to optimized the experiments processing as, at present, the design of QCL structures is already completed. In detail, first, Al0.25Ga0.75As barrier will be introduced to suppress the parasitic leakage channels, sharp interface within 1 monolayer should be achieved, meanwhile, the 2D doping levels will be increased from 3.5E10/cm2 to 5E10/cm2; second, Cu-Cu metal waveguide will developed instead of Au-Au, for better high-temperature operations. the optimized annealing temperature will be developed to avoid micro-cracks in Cu-Cu metals.
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| 次年度使用額が生じた理由 |
Due to the Cov-19 virus spread, the article costs for purchasing the high-purity k-cell Al metals is delayed to the next fiscal year, the total amount will be increased. in addition, mask patterns for Cu-Cu metals will be designed separately.
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