Particle plasmon resonances in L-shaped gold nanoparticles

We present an extensive experimental and theoretical study of the particle plasmon resonances of L-shaped gold nanoparticles. For the small characteristic size of the particles, we observe more higher-order resonances than previously from related shapes, and show that a short-wavelength resonance arises from the particle width and is not the suggested volume plasmon. We interpret the resonances through the local vector electric field in the structure and by fully taking into account the particle symmetry. (C) 2010 Optical Society of America