Coupling characteristics between one-dimensional photonic crystals and metamaterials

A couple structure composed of one-dimension photonic crystal and meta-materials realized by composite right-/left-handed transmission line (CRLH TL) is constructed by using transmission line approach. The CRLH TL exhibits a broad left-handed passband, with anti-parallel phase and group velocities. Moreover, the left-handed passband can be adjusted by the L-C elements and the unit length. The one-dimension photonic crystal is made of alternating microstrip rings and microstrip line. And the photonic passband and the stopband are determined by the lattice constant. In this paper, the first and second passbands of the photonic crystal are of interest. The coupling characteristics between the left-handed metamaterial and the photonic crystal in the first passband closely resemble that in the second passband. It is clearly observed that the coupling characteristics between left-handed metamaterial and the photonic crystal in the two passbands are similar with that between the left-handed material and the right-handed material. The photonic crystal should be regarded as a right-handed material in (the first and second) passband.