Studies On Nonlinear Optical Properties Of Gold Nanoparticle-Quantum Dot Hybrid System

A long-term goal in nonlinear optics has been the development of materials with greater nonlinear optical effects.Giant optical nonlinearities in a medium are of great importance for a broad range of applications,such as microscopy,all-optical data processing,and quantum information.Nonlinear optical effects in semiconductor nanostructures with quantum size regime have aroused great interest due to their giant nonlinearities in contrast to those of bulk counterparts,which is of great importance for developing nonlinear optical nano-devices.In semiconductor quantum systems,spherical dome nanoshells show anisotropic,highly tunable,and distinctive nonlinear optical properties compared with their shell or sphere counterparts,thereby receiving considerable attention.Surface plasmon resonances,owing to the collective oscillation of conduction band electrons in metal nanostructures,give rise to numerous interesting optical phenomena,such as squeezing light beyond the diffraction limit and large enhancements of the local electric field.Due to confining strong light field in metal surface,plasmonic structures have been explored to enhance intrinsic nonlinear optical response of materials ranging from bulk materials to quantum systems such as quantum dots.Here,basing on the quantum size effect and using quantum theory,then proposing a hybrid system made of spherical dome semiconductor nanoshells coupled to a metal nanoparticle,we explore the effect of the metal nanoparticle on the linear and nonlinear optical absorption coefficient and optical rectification index changes in the dome nanoshells with quantum sizes.The results reveal that surface plasmon resonances of metal nanoparticles greatly enhance the linear and nonlinear optical absorption coefficients of spherical dome semiconductor nanoshells with quantum sizes.These enhanced linear and nonlinear optical effects can be flexibly tuned and amplified by manipulating both the structural parameters of the nanoshells and the distance between nanoshells and metal nanoparticles.Furthermore,the bleaching effects are more clearly observed through the surface plasmon resonances.Our founding will enrich nonlinear optical effects in spherical dome semiconductor nanoshells,and make spherical dome semiconductor nanoshells a promising candidate for nonlinear optical nano-devices with the potential for integrated nonlinear optical applications.