Etude des diodes lasers émettant dans le bleu

Abstract

Abstract : The work presented in this thesis focuses on the influence of the physical parameters of the cavity on the performance of blue-emitting semiconductor lasers. Our calculations first show that the effect of quantization in quantum wells is more significant when the well width is small. This quantization becomes even more significant as the indium composition x increases. After establishing the expression to calculate the wavelength, we demonstrated that this wavelength is influenced by the well width. The optimal indium concentration to achieve the blue color ranges between x=0.2 and x=0.3. Furthermore, we calculated the maximum gain, the transparency current density, and the threshold current density as a function of the physical parameters of the cavity. We concluded that these parameters significantly influence the performance of semiconductor lasers. We also showed that the internal quantum efficiency increases with the injection current density, while the differential quantum efficiency increases as the cavity length decreases. Regarding the emitted optical power, we first showed that it varies linearly with the injection current and that the operating temperature plays a crucial role in the degradation of the emitted power. Finally, the emitted power increases with the number of quantum wells.