High-transmission defect modes in two-dimensional metallic photonic crystals

An experimental and numerical study of point defect modes in a two-dimensio nal photonic crystal of metallic rods is presented. A method is developed t o optimize the characteristics of transmission resonances in the second (an d true) photonic gap of these structures. Transmission maxima close to -2 d B have been obtained by using a combination of a small number of point defe cts. Such a value is among the highest ones reported to date for two-dimens ional photonic crystals with point defects. Besides, the width of the trans mission window is shown to be adjustable in a wide range by changing the ro d diameter. These results could be applicable to the fabrication of low-cos t and compact filters in both the microwave and near-terahertz domains. (C) 1999 American Institute of Physics. [S0021-8979(99)00212-1].