Tailoring second-order nonlinear optical effects in coupled quantum dot-metallic nanosphere structures using the Purcell effect

We study the modification of second-order nonlinear optical processes, like nonlinear optical rectification and second-harmonic generation, of a quantum dot that is coupled to a metallic nanosphere. We show that the strong variation of the spontaneous decay rate of the quantum dot near the metallic nanosphere can lead to strong enhancement or suppression of the nonlinear optical rectification and second-harmonic generation coefficients depending on the distance of the quantum dot from the surface of the nanosphere and on the direction of the electric dipole moment of the quantum dot. The nonlinear optical coefficients are also strongly influenced by the pure dephasing rate of the quantum dot.