Authors:
Shigeyuki Takagi
1
;
Tsutomu Kakuno
2
;
Rei Hashimoto
2
;
Kei Kaneko
2
and
Shinji Saito
2
Affiliations:
1
Department of Electrical and Electronics Engineering, School of Engineering, Tokyo University of Technology, 1404-1 Katakura, Hachioji, Tokyo, Japan
;
2
Corporate Manufacturing Engineering Center, Toshiba Corporation, 33 Shinisogo, Isogo, Yokohama, Kanagawa, Japan
Keyword(s):
Quantum Cascade Lasers, QCLs, Active Region, non-Equilibrium Green’s Function, Genetic Algorithm, GA, Optimization, Gain, Wavelength, Injector Barrier, Well.
Abstract:
We applied a coupled calculation of genetic algorithm and a quantum cascade laser (QCL) simulator (nextnano.QCL) to calculate the gain that excites laser light in the active region of the QCL. The film thicknesses of the nine layers constituting the active region were changed simultaneously, and the film structure with the maximum gain was determined from 1000 type of film structures. The QCL simulator incorporating a non-equilibrium Green’s function was used to calculate the gain of the QCL, and the validity of the simulation was evaluated using the active region structure reported in the previous paper. In the coupled calculation of the QCL simulator and genetic algorithms, we used gain as an objective function and methods of crossing, natural selection, and mutation simulating the evolutionary process of living organisms to optimize the thickness of nine films. As a result of the optimization calculation, the optimized structure had gain (78.44 cm–1 ) higher than that (50.01 cm–1
) in a structure reported in a previous paper.
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