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Presenter: Ghazal Hajisalem
Supervisor: Dr. Reuven Gordon

Date: Thu, December 6, 2012
Time: 15:30:00 - 00:00:00
Place: EOW 430

ABSTRACT

SUMMARY:

Metal nanoparticles are able to confine light to a sub-wavelength volume, which provides local field enhancement. This confined field is promising for achieving enhanced nonlinear optical response such as second harmonic generation. For many of plasmon nanoparticles, however, the plasmonic resonance is not at the near-infrared wavelengths of a Ti:Sapphire laser, the most common source used for ultra-fast measurements. To achieve resonance at these wavelengths, a tuning mechanism is required. This mechanism can be achieved by top-down fabrication of multi-resonant optical antenna structures. For metal nanoparticles fabricated by bottom-up methods; such as colloidally synthesized silver nanoprisms, we proposed the plasmonic hybridization approach to tune the resonance to that of the laser source.

In this presentation, we describe the plasmon hybridization between silver nanoprisms and a thin gold film, as well as optical second harmonic generation of this system. The plasmon hybrid system provided fine spectral tuning of the hybrid mode, by varying the spacer layer between the nanoprisms and the gold film. Overlapping the plasmon resonance of the system with the excitation source enhanced the second harmonic counts by approximately three orders of magnitude. The enhancement comes from fine tuning of the hybrid resonance to coincide with the excitation source.