Nonlinear optical properties in the laser-dressed two-level AlxGa1−xN/GaN single quantum well

2018 ◽  
Vol 32 (04) ◽  
pp. 1850032 ◽  
Author(s):  
Monalisa Panda ◽  
Tapaswini Das ◽  
B. K. Panda

The electronic states in the laser-dressed hexagonal and cubic Al[Formula: see text]Ga[Formula: see text]N/GaN single quantum wells are calculated using the effective mass equation. The hexagonal single quantum well contains an internal electric field due to spontaneous and piezoelectric polarizations. The effective mass equation is solved by the finite difference method. The energy levels in both cubic and hexagonal laser-dressed wells are found to increase with increase in laser dressing as the effective well widths in both the wells increase. The intersubband energy spacing between first excited state and ground state increases in the cubic quantum well, whereas it decreases in the hexagonal well due to the presence of internal electric field in it. Using the compact density matrix method with iterative procedure, first-, second- and third-order nonlinear optical susceptibilities in the laser-dressed quantum well are calculated taking only two levels. While the susceptibilities in the hexagonal well are found to get red shifted, the susceptibilities in the cubic well are blue shifted.

2000 ◽  
Vol 27 (1) ◽  
pp. 39-51 ◽  
Author(s):  
L.J Olafsen ◽  
T Daniels-Race ◽  
R.E Kendall ◽  
S.W Teitsworth

1991 ◽  
Vol 228 ◽  
Author(s):  
S. Xin ◽  
K. F. Longenbach ◽  
C. Schwartz ◽  
Y. Jiang ◽  
W. I. Wang

ABSTRACTGaAs single quantum well lasers have been successfully grown at low temperatures by a modulated beam epitaxy process in which the Al/Ga flux is held constant while the As flux is periodically shut off to produce a metal-rich surface. Devices grown at a substrate temperature of 500 °C exhibit threshold current densities below 1 kA/cm2. This value is lower than normally grown low temperature lasers and is the lowest achieved by any low substrate temperature growth technique. In addition, low temperature (10 K) photoluminescence of single quantum wells grown with this technique exhibit full-width half maximum values, comparable to that attainable by higher temperature growth techniques. The improved quality of these low temperature grown quantum structures is attributed to both a smoothing of the growth front and a reduction of excess As during the modulated beam epitaxy process. The high growth rates and less frequent shutter operation of this technique make it a more practical than migration enhanced epitaxy or atomic layer epitaxy for low temperature growth.


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