Unique Light-Matter Interaction Properties of One-Dimensional ZnO Nanomaterials

J-I Hahm
Georgetown University,
United States

Keywords: ZnO, nanowire, nanorod, nanophotonics, waveguiding, light-matter interaction, fluorescence, Raman

Summary:

This talk will present unique light-matter interaction and optical waveguiding properties observed in innate zinc oxide nanorods (ZnO NRs) as well as in ZnO NR systems near-field-coupled with external light emitters. Specifically, we reveal distinct light-matter interaction and waveguiding behaviors of single ZnO NRs pertaining to externally sourced fluorescence signals. We demonstrate that such ZnO NR properties allow ultrasensitive optical detection of protein biomarkers on the NR platforms without any chemical or biological amplification. We show that ZnO NRs can be fabricated into multiplexed, high-throughput, optical sensor arrays in a straightforward manner. In addition, multiphoton-produced optical signals waveguided through single ZnO NRs are characterized using a newly developed, scanning offset-emission hyperspectral microscopy (SOHM) technique. SOHM can be effectively used to acquire spectrally-indexed and spatially-resolved intensity maps as well as spectra of waveguided light while excitation/emission collection positions and light polarization are scanned. This capability permits us to concurrently analyze the waveguiding behaviors of different signals such as sum-frequency generation and Raman emission in individual ZnO NRs. Quantitative analyses of the different ZnO NR waveguiding behaviors can be characterized as a function of measurement position, light-matter interaction geometry, and the optical origin of the guided signal.