Guided Modes in Slab Waveguide with Central Anisotropic Metamaterial Layer

This work studies the characteristics of TE modes in a three layers slab waveguide that contains an anisotropic metamaterial as a central layer. The results show that all modes except TE₁ achieved forward propagation and then turned backwards. The effective refractive index value at which the propagation type is reversed increases with the mode order and the thickness of the middle layer. In addition, an anisotropic property in the metamaterial layer shift the modes curves (exept TE₁ ) to left or right with respect to the isotropic case. Furthermore, the mode TE₁ is abnormal and inconsistent with the behavior of other modes. Except TE₁ mode, the confinement factor is small in the forward propagation region and reaches large values in the backward propagation region.