On unusual narrow transmission bands for a multi-layered periodic structure containing left-handed materials.

Unusual narrow transmission bands are found in the Bragg reflective region of a multi-layered structure consisting of alternate right-handed material (RHM) and left-handed material (LHM). These unusual narrow transmission bands may exist no matter whether the optical length of a LHM layer completely cancels that of a RHM layer. However, if they can not cancel each other, it is required that the reflection coefficient for each interface is not too small to permit the existence of the unusual transmission bands. A non-ideal model when the LHM is dispersive and lossy is also employed to confirm the unusual transmission phenomenon.