Second-harmonic generation from bimetal composites doped with metal nanoparticles

• Second harmonic generation from bimetal composites using the nonlinear Mie theory and the effective medium theory is presented.
• The effect of temperature on the second harmonic generation is studied.
• Influence of interparticle plasmon coupling on the second harmonic generation is investigated.
• The contribution of dipolar, quadrupolar and octuolar modes is considered and discussed.

In the present paper, we study the nonlinear optical response of the bimetal composites doped with metal nanoparticles in the framework of nonlinear Mie theory combined with the Maxwell–Garnett model. We concentrate on the second-order harmonic generation from bimetal nanocomposites including silver and gold particles, since sometimes the nonlinear optical response is sensitive to the more accurate of material structure than linear optical response. We show that optical second harmonic generation is strongly sensitive to temperature as an environmental parameter, interparticle plasmon coupling between Au and Ag nanoparticles (the filling factor of inclusions), the particle size and the surrounding medium. However, this work shows good potential of bimetal composites for nonlinear optics at the nanoscale.