Resonant enhancement of second order sideband generation for intraexcitonic transitions in GaAs/AlGaAs multiple quantum wells
Resonant enhancement of second order sideband generation for intraexcitonic transitions in GaAs/AlGaAs multiple quantum wells
复制标题
GaAs/AlGaAs 多量子阱中激子跃迁的二阶边带生成的共振增强
DOI：
10.1063/1.3155189
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发表时间：
2009
影响因子：
4
通讯作者：
G. Strasser
中科院分区：
文献类型：
--
作者：
M. Wagner;H. Schneider;S. Winnerl;M. Helm;T. Roch;A. Andrews;S. Schartner;G. Strasser
介绍了一种在非掺杂对称多量子阱中有效产生二阶边带的实验研究。调谐到激子带间跃迁的近红外激光器与来自自由电子激光器的面内偏振太赫兹光束混合。太赫兹光束被调谐到激子内重空穴1s-2p跃迁或激子间重空穴-轻空穴跃迁。我们发现强烈的证据表明激子内跃迁对n=±2边带的产生有重要影响，导致在低温下转换效率提高到0.1%数量级。在室温下，对于低太赫兹功率，效率只下降了7倍。
We present an experimental study on efficient second order sideband generation in symmetric undoped GaAs/AlGaAs multiple quantum wells. A near-infrared laser tuned to excitonic interband transitions is mixed with an in-plane polarized terahertz beam from a free-electron laser. The terahertz beam is tuned either to the intraexcitonic heavy-hole 1s-2p transition or to the interexcitonic heavy-hole light-hole transition. We find strong evidence that the intraexcitonic transition is of paramount influence on n=±2 sideband generation, leading to an order-of-magnitude resonant enhancement of the conversion efficiency up to 0.1% at low temperature. At room temperature, the efficiency drops only by a factor of 7 for low terahertz powers.