Dispersion curves of surface electromagnetic waves (SEWs) in 1D silicon nitride photonic crystals having periodic surface corrugations are considered. We experimentally demonstrate that a bandgap for SEWs can be obtained by fabricating a polymeric grating on the multilayered structure. Close to the boundary of the first Brillouin zone connected to the grating, we observe the splitting of the SEW dispersion curve into two separate branches and identify two regions of very low group velocity. The proper design of the structure allows the two folded branches to lie beyond the light line in a wide spectral range, thus doubling the density of modes available for SEWs and avoiding light scattering.
© 2008 Optical Society of America
Optics at Surfaces
Original Manuscript: September 19, 2007
Revised Manuscript: December 14, 2007
Manuscript Accepted: December 16, 2007
Published: January 29, 2008
Emiliano Descrovi, Fabrizio Giorgis, Lorenzo Dominici, and Francesco Michelotti, "Experimental observation of optical bandgaps for surface electromagnetic waves in a periodically corrugated one-dimensional silicon nitride photonic crystal," Opt. Lett. 33, 243-245 (2008)