Resonance-enhanced second harmonic generation via quantum dots integrated with Ag nanoarrays

Abstract

The metal nanoarray can couple the excitation light energy to the surface, resulting in local electromagnetic field enhancement due to the resonance effect. This is beneficial to the generation of nonlinear optical processes which depend on electromagnetic resonance enhancement, taking advantage of the field enhancement properties of metal nanoarray. Here, silver nanoperiodic arrays are integrated with AgInS 2 quantum dots (QDs) to enhance the second harmonic generation (SHG) process of QDs. The experimental results show that the enhancement factor of SHG is 8.8-fold in the condition of surface plasmon resonance. In contrast, the second harmonic emission from pure quantum dots is very weak. The simulation reveals that the second harmonic enhancement is caused by the resonance between the incident laser and the Ag nanoarray. The experimental results show that it is feasible to generate a highly efficient nonlinear optical process of QDs assisted by metal nanoarray. This is beneficial for extending the nonlinear applications of quantum dots.