Anomalous group velocity at the high energy range of real 3D photonic nanostructures
Document typeConference report
PublisherSPIE-The International Society for Optical Engineering
Rights accessOpen Access
We perform a theoretical study on the group velocity for finite thin artificial opal slabs made of a reduced number of layers in the spectral range where the light wavelength is on the order of the lattice parameter. The vector KKR method including extinction allows us to evaluate the finite-size effects on light propagation in the GL and GX directions of fcc close-packed opal films made of dielectric spheres. The group is index determined from the phase delay introduced by the structure to the forwardly transmitted electric field. We show that for certain frequencies, light propagation can either be superluminal —positive or negative— or approach zero depending on the crystal size and absorption. Such anomalous behavior can be attributed to the finite character of the structure and provides confirmation of recently emerged experimental results.
CitationBotey, M.; Martorell, J. Anomalous group velocity at the high energy range of real 3D photonic nanostructures. A: SPIE Photonics Europe. "SPIE Photonics Europe". Brussel·les: SPIE-The International Society for Optical Engineering, 2010.