Enhanced transmission in near-field imaging of layered plasmonic structures.

Near-field imaging of an engineered double layer structure in transmission mode has shown enhancement of light intensity through the structure. An array created by an optically thick double layer structure of a total thickness of 165 nm containing twin 50 nm Au layers was imaged using a near-field scanning optical microscope in illumination mode. The resulting transmission image shows an increased local transmission at the position of each particle in the array. This viewable enhancement is due to a nanoantenna effect that is created by a resonant plasmon oscillation between the two layers.