| Project/Area Number |
15206034
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | Osaka University |
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Principal Investigator |
HIYAMIZU Satoshi Osaka University, Graduate School of Engineering Science, Professor, 大学院・基礎工学研究科, 教授 (50201728)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMOMURA Satoshi Osaka University, Graduate School of Engineering Science, Associate Professor, 大学院・基礎工学研究科, 助教授 (30201560)
KITADA Takahiro Osaka University, Graduate School of Engineering Science, Research Associate, 大学院・基礎工学研究科, 助手 (90283738)
OGAWA Masato Kobe University, Department of Engineering, Professor, 工学部, 教授 (40177142)
OGURA Mutsuo National Institute of Advanced Industrial Science and Technology, Nanotechnology Research Institute, Group Leader, 光技術研究部門, グループ長(研究職) (90356717)
SUGAYA Takeyoshi National Institute of Advanced Industrial Science and Technology, Photonics Research Institute, Senior Researcher, 光技術研究部門, 主任研究員(研究職) (60357259)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥47,710,000 (Direct Cost: ¥36,700,000、Indirect Cost: ¥11,010,000)
Fiscal Year 2005: ¥12,610,000 (Direct Cost: ¥9,700,000、Indirect Cost: ¥2,910,000)
Fiscal Year 2004: ¥16,900,000 (Direct Cost: ¥13,000,000、Indirect Cost: ¥3,900,000)
Fiscal Year 2003: ¥18,200,000 (Direct Cost: ¥14,000,000、Indirect Cost: ¥4,200,000)
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| Keywords | vertical cavity surface emitting laser / quantum wire / InGaAs / InAlAs / (775)B GaAs substrate / (775)B InP substrate / polarization stabilization / distributed Bragg reflector / InGaAS / (775)B GaAs基盤 / (775)B InP基盤 |
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| Research Abstract |
When quantum wires is applied to vertical cavity surface emitting lasers (VCSELs), a problem of polarization switching is expected to be resolved where the polarization direction changes by 90 degrees with increasing the excitation current of VCSELs. Quantum wires (QWRs) have preferential gain for the light with the polarization along the wire direction and stabilize the polarization of the laser light from VCSELs. There is no paper reports the stabilization of polarization for the 1.3-1.55 μm range VCSEL QWRs. The purposes of our project are to develop 1.3-1.55 μm range QWRs with (i)high density (>3 x 10^5 cm^<-1>), (ii)high uniformity (PL FWHM<10 meV at 20 K), (iii)high lateral confinement energy (>30 meV), (iv)enough high optical quality for application to laser diodes at the same time, and to achieve room temperature oscillation of QWR-VCSELs and QWR stripe laser using such high quality quantum wires. After three-years project, we achieved all of most important purposes.
Three layer
… More
s of In_<0.53>Ga_<0.47>As/In_<0.52>Al_<0.48>As QWRs were stacked and they have (i)a density of 4.5×10^5 cm^<-1>, (ii)PL FWHM of 9.7 meV at 15 K,55 meV at 300 K (iii)lateral confinement energy of 91 meV calculation, (iv)much improved optical quality by post-annealing process. The results indicate we have successfully developed high quality QWRs with four specifications at the same time. Stripe contact type laser showed room-temperature lasing at a threshold current density of J_<th>=5.3 kA/cm^3.
On the other hand, 1.55-μm range QWRs grown on (775)B InP substrates have a density of 2.4×10^5 cm^<-1> (ii)PL FWHM of 44 meV at 300 K (iii)layer thickness modulation of 3.6-10.8 nm which implies that enough high lateral confinement energy (iv)high optical quality. Only the first specification is not fulfilled. Nine stripe contact lasers show room temperature lasing at a threshold current of 4.0 kA/cm^3 (average), and 2.8 kA /cm^3 (minimum). The quantum wires were grown at a growth rate of 2 μm/h, which is two times faster than the conventional growth rate and necessary for the fabrication of 40 μm thick distributed Bragg reflector. VCSEL with the QWRs lased at 1517 nm at room temperature with a polarization parallel to the wire direction.
We also fabricated VCSELs with (775)B GaAs/(AlAs)_1(GaAs)_6 QWRs and with (775)B GaAs/(AlAs)_1(GaAs)_6 QWRs and both VCSELs showed room temperature laser oscillation. by current excitation. For the GaAs QWR VCSEL, the lasing wavelength is 769 nm and orthogonal polarization suppression ratio (OPSR) 20 dB over wide-range of current. There is no paper report the such a high OPSR value for the VCSEL with GaAs active layer. The result indicates that (775)B GaAs QWRs realizes the high stability of polarization of VCSELs. Less
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