Physics and Applications of Photonic Crystals

Abstract

We have demonstrated the resonant cavity enhanced (RCE) effect by placing microwave detectors in defect structures built around dielectric based photonic crystals. A power enhancement factor of 3450 was measured for planar cavity structures. Similar defects were used to achieve highly directional radiation patterns from monopole antennas. We also used these defect structures to demonstrate waveguiding around layer-by-layer photonic crystals. An air gap introduced between two photonic crystal walls was used as waveguide. We observed full transmission of the electromagnetic (EM) waves through these planar waveguide structures within the frequency range of the photonic band gap. The dispersion relations obtained from the experiments were in good agreement with the predictions of our waveguide model. We presented experimental and theoretical investigation of eigenmode splitting due to coupling of the localized cavity modes in the three-dimensional photonic crystals. A new type of waveguiding mechanism, photons propagate through strongly localized coupled-cavity modes, in photonic band gap structures was demonstrated. It was also observed that the group velocity of photons tends towards zero at the waveguiding band edges of the periodic coupled cavities.