Chip-Scale Plasmonic Sum Frequency Generation

Plasmonics provides a promising candidate for nonlinear optical interactions because of its ability to enable extreme light concentration at the nanoscale. We demonstrate on-chip plasmonic sum frequency generation (SFG) with a metal-dielectric-metal nanostructure. The two cross-polarized pumps (800 and 1500 nm) are designed to match the two resonances of this plasmonic nanostructure to make the most of the electric field enhancement and spatial overlapping of the modes. Since these two resonances are predominantly determined by the sizes of the top metallic nanostructures in the same direction, the SFG (521 nm) can be independently controlled by each pump via changing these sizes. This study exerts the full strength of plasmonic resonance induced field enhancement, thereby paving a way toward using nanoplasmonics for future nonlinear nanophotonics applications, such as optical information processing, imaging, and spectroscopy.