Surface plasmon coupling in hexagonal textured metallic microcavity

The coupling of surface plasmons to the photonic modes in hexagonal textured metallic microcavity was studied. Two types of sample structures (symmetric and asymmetric) were investigated. Both angle-resolved transmission and photoluminescent measurements showed the presence of surface plasmon modes for the textured metallic microcavity samples. For the asymmetric structured sample, the bandgap was observed at the Brillouin zone edge. The simulation of the photonic band structure using decoupled approximation for the standing wave modes agrees with the experimental result. We have derived the surface modes due to various interfaces in the microcavity. It was found that the surface plasmon modes from metal/air interface are most dominant, and was observed to couple strongly with both the transverse electric and transverse magnetic modes. Light extraction enhancement due to surface plasmon coupling was achieved with directional enhancement as much as 12 times compared with planar microcavity for the symmetric structured sample.