Plasmon-enhanced second harmonic generation in semiconductor quantum dots close to metal nanoparticles

摘要

We report the enhancement of the optical second harmonic signal innon-centrosymmetric semiconductor CdS quantum dots, when they are placed inclose contact with isolated silver nanoparticles. The intensity enhancement isabout 1000. We also show that the enhancement increases when the incoming laserfrequency $\omega$ is tuned toward the spectral position of the silver plasmonat $2\omega$, proving that the silver nanoparticle modifies the nonlinearemission.