Artículos de revistas
Anomalous group velocity at the high energy range of a 3D photonic nanostructure
Fecha
2010-07Registro en:
Botey, Muriel; Martorell, Jordi; Dorado, Luis Antonio; Depine, Ricardo Angel; Lozano, Gabriel; et al.; Anomalous group velocity at the high energy range of a 3D photonic nanostructure; Optical Society of America; Optics Express; 18; 15; 7-2010; 15682-15690
1094-4087
CONICET Digital
CONICET
Autor
Botey, Muriel
Martorell, Jordi
Dorado, Luis Antonio
Depine, Ricardo Angel
Lozano, Gabriel
Míguez, Hernán
Resumen
We report on a study of electromagnetic waves propagation in thin periodically ordered photonic nanostructures in the spectral range where the light wavelength is on the order of the lattice parameter. The vector KKR method we use allows us to determine the group index from finite photonic structures including extinction providing confirmation of recently emerged results. We show that for certain frequencies the group velocity of opal slabs can either be superluminal or approach zero depending on the crystal thickness and the unavoidable presence of losses. In some cases, group velocity can be negative. Such behavior can be clearly attributed to the finite character of the three-dimensional structure and reproduces previously reported experimental observations. Calculations show that contrary to the predictions of extraordinary group velocity reductions for infinite periodic structures, the group velocity of real opals may exhibit strong fluctuations at the high energy range. Hence, a direct identification between the calculated anomalous group velocities, for an actual opal film, and the predicted propagating low dispersion modes for an ideal infinite ordered structure seems difficult to establish. © 2010 Optical Society of America.