Experimental demonstration of complete photonic band gap in graphite structure

We experimentally demonstrate the existence of complete photonic band gap ill graphite-type photonic crystals, thereby confirming theoretical predictions reported in previous studies. Experiments are performed at microwave frequencies from 27 to 75 GHz using hexagonal lattices of alumina rods. Transmission spectra measured for E (Tm) and H (TE) polarizations and for different orientations of the two-dimensional lattice are found to be in excellent agreement with numerical calculations. The complete photonic band gap results from the overlap of E-7 and H-5 forbidden bands. Attenuations larger than 30 dB are measured for structures comprised of only four rows of alumina rods. (C) 1997 American Institute of Physics.