Extraordinary optical transmission of multimode quantum correlations via localized surface plasmons.

We demonstrate the transduction of macroscopic quantum correlations by Ag localized surface plasmons (LSPs). Quantum noise reduction, or squeezed light, generated through four-wave mixing in Rb vapor, is coupled to a Ag nanohole array designed to exhibit LSP-mediated extraordinary-optical transmission spectrally coincident with the squeezed light source at 795 nm. This first demonstration of the coupling of quantum light into LSPs conserves spatially dependent quantum information, allowing for parallel quantum protocols in on-chip subwavelength quantum information processing.