Ahmad Mohammadi

In this thesis, we investigate the effect of periodic arrays of elliptical cross-section gold and silver nanoparticles on Plasmon-enhanced nanolasers. First, the theory of classical Maxwell's equations and their coupling with quantum rate equations is reviewed. Then, using the finite-difference time-domain method, the model is numerically solved, and the results are discussed. We demonstrate how nanoparticles arranged in a periodic lattice affect the performance of nanoplasmonic lasers. The optical properties of gold nanoparticle arrays are also examined, and the influence of Bragg modes on the coupling of diffracted waves with plasmonic modes is analysed. We show that by matching the resonance frequency of the structure with the absorption frequency of the gain atoms, lasing action can be achieved in such structures. The formation of hybrid photonic-plasmonic modes enhances lasing efficiency. Furthermore, we demonstrate that silver nanoparticles exhibit better lasing performance compared to gold nanoparticles.