The relative probability of two- and three-photon absorption in Au nanoparticles was adjusted by tuning thesurface-plasmon-resonance (SPR) wavelength and the excitation intensity. Consequently, highly efficient three-photon luminescence from Au nanoparticles with strong SPR enhancement was observed. The decay rate andpolarization of two- and three-photon luminescence from Au nanoparticles were comparatively studied.Furthermore, the multiphoton luminescence from Au nanoparticles was used to investigate the resonant energytransfer from CdSe semiconductor quantum dots.
