GaAs/ AlAs Multilayer Cavity with Er-Doped InAs Quantum Dots Embedded in Strain-Relaxed InGaAs Barriers for Ultrafast All-Optical Switches
GaAs/ AlAs Multilayer Cavity with Er-Doped InAs Quantum Dots Embedded in Strain-Relaxed InGaAs Barriers for Ultrafast All-Optical Switches
复制标题
用于超快全光开关的具有嵌入应变松弛 InGaAs 势垒中的掺铒 InAs 量子点的 GaAs/ AlAs 多层腔
DOI：
10.1143/jjap.51.04dg06
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发表时间：
2012
影响因子：
1.5
通讯作者：
Toshiro Isu
中科院分区：
文献类型：
--
作者：
Hyuga Ueyama;Tomoya Takahashi;Yoshinori Nakagawa;Ken Morita;Takahiro Kitada;Toshiro Isu
掺Er InAs量子点（QD）嵌入应变弛豫InGaAs势垒中，由于无辐射过程，其载流子衰减时间非常短，仅为3 ps，是GaAs/AlAs多层腔超快全光开关的上级材料。通过增加应变弛豫InGaAs势垒中的In组分，同时保持极短的衰减时间，增加了由于掺Er量子点的20层堆叠中的吸收饱和引起的非线性信号的强度。采用分子束外延技术生长了由GaAs/AlAs多层膜和半波长腔层组成的量子点腔结构，该腔层由两层掺铒量子点组成。在腔模波长为1.55 µm的时间分辨测量中清楚地观察到透射变化信号。掺铒量子点腔的响应时间为4 ps，比未掺杂量子点腔的响应时间（12 ps）要短得多。
Er-doped InAs quantum dots (QDs) embedded in strain-relaxed InGaAs barriers, which exhibit an extremely short carrier decay time of 3 ps due to the nonradiative process, are superior materials for ultrafast all-optical switches using a GaAs/AlAs multilayer cavity. The intensity of the nonlinear signal due to the absorption saturation in the 20-layer stack of the Er-doped QDs was increased by increasing the In composition in the strain-relaxed InGaAs barriers while keeping the extremely short decay time. The QD cavity structure, which consisted of GaAs/AlAs distributed Bragg reflector (DBR) multilayers and a half-wavelength cavity layer containing two layers of the Er-doped QDs was grown by molecular beam epitaxy. The transmission change signal was clearly observed in the time-resolved measurements at the cavity mode wavelength of 1.55 µm. The response time of 4 ps was observed for the Er-doped QD cavity, which was much shorter than that (12 ps) for the undoped QD cavity.