Nanoprobes for nano-femto optics

Intellectual merit: The goal of the proposed research is to develop a nonlinear nanoprobe for nano-femto scale spatiotemporal characterization of ultrafast optical near fields. The proposed nanoprobe consists of a nonlinear nanoparticle attached to a nanowire, which is in turn attached to a silica fiber taper. The nonlinearity of the nanoparticle enables temporal characterization through autocorrelation or frequency resolved optical gating measurements while the nanoscale spatial resolution is achieved through near field scanning of the nonlinear nanoparticle. We will develop two-photon fluorescent and second harmonic nanoprobes, develop and optimize nanoprobe based spatiotemporal characterization technique, and investigate the precision of the proposed nanoprobe based method. With the unique capabilities of the proposed nonlinear nanoprobes, we also plan to investigate their applications to probing several interesting ultrafast optical near fields.

Broad impact: The proposed nanoprobe can significantly advance the state of the art of nano & ultrafast technology, which can in turn create far-reaching impacts in many scientific disciplines in which they play a central role. With its unique capability in providing nano-femto scale spatiotemporal mappings, the proposed nonlinear nanoprobe can find many important applications. Fundamental questions with regard to light-matter interaction in the ultrafast regime, ultrafast dynamics of complex nanostructures, and nonlinear optics in nanoscale plasmonic structures, can all benefit from the development of the proposed nanoprobe. As a result, the proposed research can have considerable impact on areas such as nonlinear optical microscopy and nanophotonics. The proposed research is highly interdisciplinary and can also provide excellent education opportunities for students.