This letter reports near-field optical observations of light energy transport along micro-waveguides decorated by short chains of gold "nanodots". In spite of their subwavelength dimensions (100 $\unnm$ diameter $\times 20$ $\unnm$ height), the metallic dots in the chain function as an efficient photonic band filter or a nanometric Bragg mirror. Numerical simulations reproduce the observed phenomenon and indicate that the occurrence of a band gap for light transport through the decorated guide corresponds to a selective absorption by the metallic chain.
DOI: 10.1209/epl/i2003-10268-x
View online : Europhys. Lett. 66, 785 (2004)