OPTIMIZING THE Q-VALUE IN 3-DIMENSIONAL METALLIC PHOTONIC BAND-GAP CRYSTALS

A metallic photonic band gap crystal with different defect structures is fabricated. The structure is designed and built to operate in the 8 -26 GHz frequency range. Defects with sharp peaks in the transmission are created by removing portions of the metallic rods in a single defe ct layer. A high quality factor (Q) for the defect state is obtained b y larger filling ratios and spatial separations between the unit cells . An optimized value of Q greater than or equal to 300 is found for th ree unit cell metallic photonic band gap structure. The experimental o bservations agree very well with theoretical calculations using the tr ansfer matrix method. (C) 1998 American Institute of Physics. [S0021-8 979(98)04320-5].