| Project/Area Number |
10450115
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
|
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
ARAI Shigehisa Research Center for Quantum Effect Electronics Tokyo Institute of Technology, Professor, 量子効果エレクトロニクス研究センター, 教授 (30151137)
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| Project Period (FY) |
1998 – 2000
|
| Project Status |
Completed (Fiscal Year 2000)
|
| Budget Amount *help |
¥12,600,000 (Direct Cost: ¥12,600,000)
Fiscal Year 2000: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1999: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1998: ¥6,000,000 (Direct Cost: ¥6,000,000)
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| Keywords | Semiconductor laser / Quantum wire laser / Strained quantum wire lasers / Multiple micro cavity laser / GaInAsP compound crystal / Electron beam lithography / Organo-metallic vapor phase epitaxy / Dry etching |
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| Research Abstract |
In this work, in order to realize extremely low current and high efficiency operation of long-wavelength semiconductor lasers for optical communications, we have investigated low-damage fabrication process of bi-axially strained quantum wire and quantum-box structures.
Results obtained in this research are summarized as follows.
1) 1.5μm-wavelength GaInAsP/InP compressively strained quantum-wire lasers were fabricated by electron beam lithography, and 2-step organic metal vapor phase epitaxy growth. Double layered stacked quantum-wire lasers with the wire width of 21nm in the period of 100nm were realized for the first time by adopting reactive-ion-etching (RIE) with CH_4/H_2 gas mixture.
2) In order to reduce non-radiative recombination centers at the etched/regrown interfaces due to a strain relaxation, strain compensated multiple-quantum-well (MQW) structure was used as an initial wafer and lasers consisting of stacked multiple (5 layered) wirelike active regions (the wire width of 43n
… More
m in the period of 100nm) were realized. As the result, threshold current density as low as 318A/cm^2, which is almost 60% of MQW lasers obtained from the initial wafer, was obtained at room temperature. Not only a low threshold current density operation but also high differential quantum efficiency operation were obtained up to 85℃. This fact clearly indicates that the fabrication process employed in this research is promising as a low-damage realization method of ultra-fine structures.
3) By using our newly developed method, we realized a new type of distributed feedback (DFB) lasers consisting of periodically arranged double layered wirelike active regions. As the results, a record low threshold current density of 94A/cm^2 (20μm wide stripe) and a record low threshold current of 0.7mA (2.3μm wide BH stripe) as well as differential quantum efficiency of 23%/facet were achieved at an emission wavelength of 1.55μm. Moreover, superior single-mode-properties attributed to the matching between the standing wave profile and the position of the active region were clarified for the first time. Less
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