Experimental Verification of Complex Dispersion Relation in Lossy Photonic Crystals

Abstract

The complex wave number in lossy photonic crystals composed of microplasmas was verified experimentally by measuring the refractive index and the transmittance in a microwave range. These experimental results coincide with the dispersion relation obtained by a modified plane-wave expansion method. In particular, an extraordinary reduction of attenuation was observed in a certain frequency band, which is attributed to a loss term in the dielectric function and periodicity in the structure. These results indicate that a method of dynamic control for electromagnetic waves can be realized using of the dispersion relation in complex space.