Surface Plasmon Enhanced Si:Er Infrared Light Emitting Diodes

摘要

We have developed a general methodology to model spontaneous emission enhancements of optical emitters by plasmonic nanoparticles. The results are of importance for the development of Si-based light sources (lasers, LEDs) that operate at visible or infrared frequencies. Novel theory was developed for ellipsoidal particles, that serve as a model system for anisotropic particles in general. We experimentally demonstrated plasmon- enhanced emission from optically active erbium ions (emission at 1.5 microns) and Si quantum dots (emission 600-1000 nm). We demonstrated for the first time control and tuning of the Si quantum dot spontaneous emission spectrum using plasmonic coupling and as well as polarization controlled emission from Si quantum dots. Finally, we demonstrated a Si-based plasmon-enhanced LED based on Si quantum dot emission. Throughout this MURI program the project was expanded to include the development cathodoluminescence imaging spectroscopy as a novel tool to study the propagation, confinement and damping of surface plasmons and the development of focused ion beam milling as a technique to fabricate photonic nanostructures. We studied dispersion of isolated coaxial plasmonic nanostructures, in which we discovered optical modes with negative refractive index. This then led to the development of the first single-layer wide-angle negative index metamaterial at visible frequencies.