Non-linear optical devices utilizing triply coupled asymmetric GaAs quantum wells

利用三重耦合不对称 GaAs 量子阱的非线性光学器件

• 批准号: 10555103
• 负责人: SAWAKI Nobuhiko
• 金额: $ 8.26万
• 依托单位: NAGOYA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10555103/
• 关键词: optical modulator; coupled quantum wells; tunneling; GaAs; optical nonlinearity; femto-second spectroscopy; optical device; Quantum confined Stark effect; ホトルミネッセンス; 非線形デバイス; 光変調; ポンプ・プローブ法; 電子・正孔対; 準位共鳴

The semiconductor quantum well has been expected to be one of the components in the field of opto-electronic devices with high speed, high density and high sensitivity. In this study, the resonance phenomena in a coupled quantum well system is investigated in terms of the tunneling of carriers to develop a ultra-high speed optical switching device.(1)The transmission in a asymmetrically coupled triple quantum wells made by GaAs/AlGaAs hetero-structure exhibited a strong nonlinear behavior as a function of the incident optical intensity. It was dependent on the wavelength, determined by the relative widths of the quantum wells.(2)The femo-second pump-probe method was applied to investigate the response of the device, It was shown that the non-linear behavior occurs within a few pico-seconds.(3)The response of the transmission and flenectance were investigated as a function of the wavelength of the incident laser light. At a wavelength which corresponding to the narrowest well exciton, the carrier density was found to decrease with a time constant of 3-4 ps. On the other hand, at a wavelength corresponding to the widest well exciton, the carrier density increased with a time constant of 4-5 ps. This suggests the occurrence of the electron transfer between these wells. This proves that the nonlinear behavior is due to the different tunneling time of electrons from that of holes.(4)The Stark shift of the PL spectra showed one to one correspondence to the non-linear behavior of the transmission.

半导体量子阱有望成为高速、高密度、高灵敏度光电子器件的重要组成部分之一。本研究以超高速光开关元件为研究对象，探讨耦合量子井系统中的共振现象。（1）GaAs/AlGaAs异质结构非对称耦合三量子威尔斯阱的透射率随入射光强的变化呈现出强的非线性特性。它取决于波长，由量子威尔斯的相对宽度决定。（2）利用飞秒泵浦-探测方法研究了器件的响应特性，发现器件在几皮秒内具有非线性响应。（3）研究了透射率和反射率随入射激光波长的变化规律。在对应于最强阱激子的波长处，载流子密度随时间常数的减小而减小，时间常数为3- 4ps。另一方面，在对应于最宽阱激子的波长处，载流子密度以4-5 ps的时间常数增加。这表明在这些威尔斯阱之间发生了电子转移。这证明了非线性行为是由于电子和空穴的隧穿时间不同。（4）光致发光谱的Stark位移与透射率的非线性行为具有一一对应的关系。

项目成果

安亨洙: "三重量子井戸構造による光非線形性とその高速応答" 応用物理. 67・11. 1290-1294 (1998)

安亨洙：“三量子阱结构带来的光学非线性及其高速响应”应用物理学67・11（1998）。

K.Mizutani,: "Tunneling and Nonlinear Optical Response in an Asymmetric GsAs/AlGaAs Triple Quantum Well Structure,"International Conference on Superlattices, Microstructures, and Microdevices 2000. 61-62 (2000)

K.Mizutani，：“非对称 GsAs/AlGaAs 三量子阱结构中的隧道和非线性光学响应”，超晶格、微结构和微器件国际会议 2000. 61-62 (2000)

N.Sawaki: "Electron tunneling time into a quantum disk" Fourth International symposium on new phenomena in mesoscopic structures(NPMS 98) Kauai,1998. 27-229 (1998)

N.Sawaki：“电子隧道时间进入量子盘”第四届介观结构新现象国际研讨会（NPMS 98）考艾岛，1998 年。

N.Sawaki: "Pico-second non-linear optical transmission in an asymmetric triple quantum well structure"Physica E. (印刷中). (2000)

N.Sawaki：“非对称三量子阱结构中的皮秒非线性光学传输”Physica E.（出版中）。

H.S.Ahn: "Fast response of the optical nonlinearity in a GaAs/AlGaAs asymmetric triple quantum well strucutre"J.Korean Physical Society. 34. 263-267 (1999)

H.S.Ahn：“GaAs/AlGaAs 不对称三量子阱结构中光学非线性的快速响应”J.韩国物理学会。