Technical: This research project addresses active plasmonic materials and prototype devices. Plasmonics has focused largely on passive metallodielectric structures to control wave dispersion and propagation in planar waveguides, subwavelength scale apertures and nanoparticle arrays. While passive plasmonic materials enable plasmonic components interconnected in circuit-like networks, greater functionality will be possible in plasmonic components and networks if active plasmonic materials/devices can be realized. The approach centers on synthesis and characterization of new plasmonic materials which may enable plasmon emission, nonlinearity and gain for potential plasmonic device applications. The goal is to form the materials foundation for enabling compact plasmonic sources and nonlinear plasmonic and nanophotonic components useful for integration into nanophotonic circuits containing linear and nonlinear elements for applications such as chip-based optical switching, imaging, and molecular spectroscopy. The concepts and materials research addresses three specific application areas. The first is materials research for realization of ultracompact subwavelength photonic switches based on electro-optical and nonlinear optical modulation of plasmonic hole-array and nanoparticle array transmission. The second area is realization of surface plasmon emission sources, including light-emitting structures featuring plasmon-enhanced light emission and spectrally-tuned spontaneous emission as well as purely bound plasmon-generating material configurations. The third area is the design and confinement of plasmonic modes within subwavelength mode volumes in annular Bragg resonator surface plasmon cavities. Investigation of these structures is expected to yield new insights about the nature of surface electromagnetic wave propagation and scattering at metal interfaces and the radiative emission properties of quantum dots and dipole emitters strongly perturbed by local fields near metallic nanostructures. The approach includes theoretical and experimental activities. Theoretical work will focus on analytic modeling as well as full-field electromagnetic simulations using finite difference time domain and beam propagation methods that guide the design of plasmonic structures. Experimental work will focus on developing active plasmonic structure fabrication, including lithographic fabrication of plasmonic cavities, integration of active semiconductor nanocrystal media (Si, CdSe and the IV-VI lead salts PbS and PbSe).
The project addresses basic research issues in a topical area of materials science having high technological relevance. The research will contribute basic materials science knowledge at a fundamental level to new understanding and capabilities for potential next generation electronic/photonic devices. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. The project includes i) training of graduate researchers in the emerging areas of plasmonics and nanophotonics ii) educational outreach to minority undergraduate students via summer undergraduate research at Caltech and iii) research dissemination in the worldwide plasmonics community via a newly-founded Gordon Research Conference on plasmonics, to be held for the first time in summer 2006. Graduate research training involves materials science and applied physics of surface plasmon emission sources and nonlinear phenomena in plasmonic materials. Minority undergraduate students will be identified through Caltech's Minority Undergraduate Fellowship program, GradPreview program and via interactions with the Materials Partnership between Caltech and California State University Los Angeles. The principal investigator will serve as Vice-Chair of the new Plasmonics Gordon Conference, whose goal is to advance the plasmonics field through stimulating interdisciplinary presentation and discussion at the frontiers of science.
