Multipolar Plasmon Resonances in Individual Ag Nanorice

We study the optical excitation of high-order surface plasmon resonance modes in individual Ag nanorice particles using dark-field scattering spectroscopy. We analyze the results by model calculations using the boundary element method. Symmetry breaking caused by oblique illumination makes the even order resonance modes observable in the optical spectrum. All the resonance peaks are found to redshift with increasing length of the particle.