Plasmonic Coupling of a Gold Colloid and a Gold Film

Engineering of plasmon resonances is important for a variety of applications, including but not limited to surface enhanced Raman spectroscopy (SERS) and near field scanning optical microscopy (NSOM). Of special interest are systems where the plasmons of a nanoparticle and a thin gold film are coupled.~ This coupling allows for a greater degree of control of the plasmon resonance of the system, as well as a strong, localized, enhancement of the incident electric field.~ We demonstrate that this coupling, and the resulting enhancement, can be used for SERS applications, and explore its impact on potential NSOM applications.