GENERATION AND PROPAGATION OF SURFACE PLASMON POLARITONS ON WEDGE-LIKE PLASMONIC WAVEGUIDE USING SEMICONDUCTOR QUANTUM DOT

Abstract

Propagating surface plasmon concentrates light energy beyond the diffraction limit and travels at speeds close to the speed of light, making it a possible alternative for electrical on-chip interconnects-a major performance-limiting component in microprocessors. Using surface plasmon as information carrying medium requires optimal excitation and propagation strategy. Herein we investigate how colloidal quantum dots realize surface plasmon generation and propagate along wedge-like gold waveguides. We fabricated wedge-like plasmonic waveguides and positioned colloidal QDs at desired locations on the wedge apexes using electrohydrodynamic printing technique. Far-field optical imaging provided evidence of SPP generation and clear indication of SPP confinement along the apex regions. Unlike typical quantum dot-based LEDs that maximizes photon generation, the monolayer of quantum dots placed close proximity to the electrode makes use of quenching effect of the metal to transfer the exciton energy into the bottom electrode and subsequently sustains the generation of surface plasmons.