@article { ISI:000305106400028,
	title = {Near-Normal Incidence Dark-Field Microscopy: Applications to Nanoplasmonic Spectroscopy},
	journal = {NANO LETTERS},
	volume = {12},
	number = {6},
	year = {2012},
	month = {JUN},
	pages = {2817-2821},
	publisher = {AMER CHEMICAL SOC},
	type = {Article},
	address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA},
	abstract = {The spectroscopic characterization of individual nanostructures is of fundamental importance to understanding a broad range of physical and chemical processes. One general and powerful technique that addresses this aim is dark-field microscopy, with which the scattered light from an individual structure can be analyzed with minimal background noise. We present the spectroscopic analysis of individual plasmonic nanostructures using dark-field illumination with incidence nearly normal to the substrate. We show that, compared to large incidence angle approaches, the near-normal incidence approach provides significantly higher signal-to-background ratios and reduced retardation field effects. To demonstrate the utility of this technique, we characterize an individual chemically synthesized gold nanoshell and a lithographically defined heptamer exhibiting a pronounced Fano-like resonance. We show that the line shape of the latter strongly depends on the incidence angle. Near-normal incidence dark-field microscopy can be used to characterize a broad range of molecules and nanostructures and can be adapted to most microscopy setups.},
	keywords = {Dark field, Fano resonance, nanoplasmonics, nanoshell, polarization, spectroscopy},
	issn = {1530-6984},
	doi = {10.1021/nl300160y},
	author = {Fan, Jonathan A. and Bao, Kui and Lassiter, J. Britt and Bao, Jiming and Naomi J. Halas and Peter Nordlander and Federico Capasso}
}
