Ultrafast gain recovery and large nonlinear optical response in submonolayer quantum dots
Ultrafast gain recovery and large nonlinear optical response in submonolayer quantum dots
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DOI：
10.1103/physrevb.94.014305
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发表时间：
2016-07
影响因子：
3.7
通讯作者：
B. Lingnau;K. Lüdge;B. Herzog;M. Kolarczik;Y. Kaptan;U. Woggon;N. Owschimikow
中科院分区：
文献类型：
--
作者：
B. Lingnau;K. Lüdge;B. Herzog;M. Kolarczik;Y. Kaptan;U. Woggon;N. Owschimikow
Submonolayer quantum dots combine the zero-dimensional charge-carrier confinement of self-assembled quantum dots with the large density of states of a quantum well. Electroluminescence and pump-probe experiments on a submonolayer-based optical amplifier show that the system exhibits a high gain of $90{\mathrm{cm}}^{\ensuremath{-}1}$ and an ultrafast gain recovery. We propose a rate equation system describing the microscopic carrier dynamics which quantitatively reproduces the observed behavior and provides deeper theoretical understanding of the material system. In contrast to Stranski-Krastanov quantum dots, the fast gain recovery is enhanced by a strong interdot coupling. Optically inactive submonolayer states form an efficient carrier reservoir and give rise to a large nonlinear optical response.
