Heavy-hole and light-hole quantum beats in the polarization state of coherent emission from quantum wells

1999 ◽  
Vol 35 (4) ◽  
pp. 523-531 ◽  
Author(s):  
A.L. Smirl ◽  
X. Chen ◽  
O. Buccafusca
1999 ◽  
Vol 60 (11) ◽  
pp. 8267-8275 ◽  
Author(s):  
Arthur L. Smirl ◽  
Martin J. Stevens ◽  
X. Chen ◽  
O. Buccafusca

1990 ◽  
Vol 57 (1) ◽  
pp. 19-21 ◽  
Author(s):  
Karl Leo ◽  
Theo C. Damen ◽  
Jagdeep Shah ◽  
Ernst O. Göbel ◽  
Klaus Köhler

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Takuya Kawazu

Optical properties of GaAs/AlGaAs quantum wells (QWs) in the vicinity of InAlAs quantum dots (QDs) were studied and compared with a theoretical model to clarify how the QD strain affects the electronic states in the nearby QW. In0.4Al0.6As QDs are embedded at the top of the QWs; the QD layer acts as a source of strain as well as an energy barrier. Photoluminescence excitation (PLE) measurements showed that the QD formation leads to the increase in the ratio Ie-lh/Ie-hh of the PLE intensities for the light hole (lh) and the heavy hole (hh), indicating the presence of the valence band mixing. We also theoretically calculated the hh-lh mixing in the QW due to the nearby QD strain and evaluated the PLE ratio Ie-lh/Ie-hh.


2007 ◽  
Vol 17 (01) ◽  
pp. 115-120
Author(s):  
N. Sustersic ◽  
S. Kim ◽  
P.-C. Lv ◽  
M. Coppinger ◽  
T. Troeger ◽  
...  

In this paper, we report on current pumped THz emitting devices based on intersubband transitions in SiGe quantum wells. The spectral lines occurred in a range from 5 to 12 THz depending on the quantum well width, Ge concentration in the well, and device temperature. A time-averaged power of 15 nW was extracted from a 16 period SiGe/Si superlattice with quantum wells 22 Å thick, at a device temperature of 30 K and a drive current of 550 mA. A net quantum efficiency of approximately 3 × 10-4 was calculated from the power and drive current, 30 times higher than reported for comparable quantum cascades utilizing heavy-hole to heavy-hole transitions and, taking into account the number of quantum well periods, approximately four times larger than for electroluminescence reported previously from a device utilizing light-hole to heavy-hole transitions.


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