We report the experimental observation of a trapped rainbow in adiabatically graded metallic gratings, designed to validate theoretical predictions for this unique plasmonic structure. One-dimensional graded nanogratings were fabricated and their surface dispersion properties tailored by varying the grating groove depth, whose dimensions were confirmed by atomic force microscopy. Tunable plasmonic bandgaps were observed experimentally, and direct optical measurements on graded grating tructures show that light of different wavelengths in the 500-700-nm region is "trapped" at different positions along the grating, consistent with computer simulations, thus verifying the "rainbow" trapping effect.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Mar 29 2011|
Bibliographical noteGenerated from Scopus record by KAUST IRTS on 2022-09-13
ASJC Scopus subject areas