Local Electromagnetic Fields Surrounding Gold Nano-Cap Particles

Using the discrete dipole approximation (DDA) the local electromagnetic fields surrounding gold nano-cap particles are investigated. Suitable k-vectors and polarization vectors of the incident light are used to determine the largest local electric field enhancement. The largest enhancement can be found for the 864 nm dipole resonance; where the field enhancement is approximately 30 000 times the applied field. The electric field contours surrounding the particle are used to assign the order of the surface plasmon resonances.