A Metal-Insulator-Metal based two-dimensional triangular lattice photonic band-gap structure

We present a two-dimensional (2D) photonic crystal with subwavelength light confinement in the transverse direction perpendicular to the planar structure based on the metal-insulator-metal (MIM) configuration. Periodic modulation in the dielectric region of MIM waveguides creates forbidden frequency ranges, known as photonic band-gaps. Using a modified two dimensional plane wave expansion (PWE) technique, we calculate the band structure of the plasmonic photonic crystal. The resulting band structure is verified by finite-difference time-domain simulations. We show that the band-gap of the slab-like MIM-based photonic crystal is wider than the band-gap of the two dimensional dielectric photonic crystal. The MIM-based photonic crystal structure presents a solution to the problem of degradation of band-gap and light escaping in two-dimensional slab photonic crystals.