Optical Nonlinearities Enhanced by Near-Field Diffraction in Artificial Dielectric Nanostructures

University Of California-San Diego, La Jolla CA

Investigators

Abstract

9912476 Fainman Given the enormous increase in communication capacity provided by high bandwidth optical fibers, new technologies will soon be necessary to provide ultra-high bandwidth switching and networking capabilities. The bandwidth available in optical fibers is currently exploited using wavelength and time division multiplexing techniques, both of which increasingly rely on the ability to generate, detect, switch, multiplex and demultiplex optical information-carrying waves using direct efficient nonlinear optical interactions. Growth in the capabilities and applications of these technologies using existing nonlinear optical materials and devices is limited by efficiency (due to the relatively small effective nonlinear coefficients and the short effective interaction lengths imposed by dephasing). The goal of this proposal is to conduct basic research towards the development of efficient optical nonlinearities exploiting the near field interactions in artificial nanostructures. The proposed approach will focus on: (i) enhancement of optical nonlinearities by engineering nanostructures that exhibit local-field concentration, (ii) incorporation of the optical nonlinearity enhancement due to the very high field effects achievable with ultrashort laser pulses, and (iii) engineering broadband phase-matching nano- and micro-structures to meet the needs of optoelectronic and imaging systems (e.g., using the unique properties of photonic crystals to allow operation in broad angular and wavelength bands). The specific objectives of this proposal include rigorous modeling, design, fabrication and characterization of these novel nonlinear optical nanostructures. Special emphasis will also be given to our ultimate objective of using these enhanced optical nonlinearities to build functional meso-optic devices and components that will have a significant impact on optical communication networks (e.g. wavelength converters, space-to-time and time-to-space demultiplexers, switches, etc.) and imaging systems (e.g. time-gating for biomedical imaging), as well as on additional novel applications (e.g. higher order harmonic generation for high-resolution optical lithography). The proposed research will not only have a significant impact on the development of all-optical nonlinear processors for optical communication networks and imaging systems, but also result in development of the basic technology for studying the near field nonlinear optical effects in meso-scale optical architectures. The proposed studies will also advance the basic science and engineering in such areas as vector optical wave diffraction in near-field nonlinear dielectric nanostructures, understanding of nonlinear optical processes in nanostructured materials, and fabrication of such devices using deposition and ion implantation techniques. The proposed project will also play a unique role in the education and development of human resources in science and engineering at the graduate and undergraduate levels, as under our prior NSF support (contributing to over 100 manuscripts in refereed journals and conference presentations, the completion of 6 Ph.D. and 5 M.Sc. degrees, NSF REU for 8 undergraduate students, and the current supervision of 10 Ph.D. students). ***