Photon tunneling in composite layers of negative- and positive-index media

The photon tunneling phenomena in the composite barrier of both positive index material and negative index medium (NIM) are analyzed. A negative barrier-length concept is introduced for the tunneling photon in the NIM, which facilitates the analysis of a composite barrier. In addition to transmission and reflection coefficients, some comments on the post-tunneling position and stationary-phase tunneling time are given.