Optically-driven collapse of a plasmonic nanogap self-monitored by optical frequency mixing

Nathaniel K Grady; Mark W Knight; Rizia Bardhan; Naomi J Halas

doi:10.1021/nl100759p

Optically-driven collapse of a plasmonic nanogap self-monitored by optical frequency mixing

Nano Lett. 2010 Apr 14;10(4):1522-8. doi: 10.1021/nl100759p.

Authors

Nathaniel K Grady¹, Mark W Knight, Rizia Bardhan, Naomi J Halas

Affiliation

¹ Laboratory for Nanophotonics, Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA.

PMID: 20353196
DOI: 10.1021/nl100759p

Abstract

A nanoparticle separated from a metallic surface by a few-nanometer thick polymer layer forms a nanoscale junction, or nanogap. Illuminating this structure with ultrashort optical pulses, exciting the plasmon resonance, results in a continuous, monitorable collapse of the nanogap. The four-wave mixing signal generated by this illumination of the nanogap provides a simultaneous monitoring of the collapse, increasing dramatically upon gap closure. Collapse is irreversible, occurring with simultaneous ablation of the dielectric from the junction.