Nonlinear Dynamics in Optoelectronics Structures with Quantum Well

Abstract

The author presents some results on nonlinear dynamics in optoelectronics nanostructures as lasers with quantum wells and quantum well solar cells using mathematical modeling and numerical simulations of the phenomena which take place in such kinds of structures. The nonlinear dynamics takes the complexity of the phenomena into account, which govern the field-substance interaction. Computational software was elaborated to study the nonlinear phenomena in such quantum devices, which put into evidence their complex nonlinear dynamics, characterized by bifurcation points and chaos, and the critical values of the parameters being determined. The mathematical modeling and numerical simulations for the quantum well solar cells for optimizing the values of their optical parameters (refraction index, reflectance, and absorption) were also analyzed, so that the conversion efficiency of the devices can be improved. Although in our study we have considered only rectangular quantum wells, the hybrid model allows computing the optimum values of the parameters whatsoever the form of the quantum wells. The developed numerical models and the obtained results are consistent with the existing data in the literature for the optoelectronics of quantum well structures, having important implications in the applications.

Basic research for designing the erbium doped fiber amplifier in long distance cable communications

“…The study of the functional characteristics of QWL is possible based on the model presented above and others [27], using MATHCAD programs for integrating these equations, using the appropriate algorithms. A comparative study of the models presented for lasers with quantum wells is possible by numerically integrating the corresponding equations for different types of pumping signals [28][29][30].…”

“…The system of linear equations of the small signal model written in a matrix form easily implemented in MATHCAD has the form (3.3). The values of the model parameters are given in [27].…”

“…The total carrying capacity of submarine cables is in the range of terabits per second, while satellites typically offer only 1,000 megabits per second, so that the superiority of the submarine cables in comparison with other systems of information transmission is demonstrated. The paper presents the author's research on optical fiber amplifiers and Quantum Well Lasers (QWL) diodes, the results being important in communications, especially those used in long distance transoceanic and intercity systems for information transmisson [8,27,30].…”