Lateral shifts of an optical beam in an anisotropic metamaterial slab

The lateral shift of a light beam at the surface of an anisotropic metamaterial slab is investigated. Analytical expressions of the lateral shifts are derived using the stationary-phase method, in the case that total reflection does and does not occur at the first interface. The sign of the lateral shift in two situations is discussed, and the necessary conditions for the lateral shift to be positive or negative are given. It is shown that the thickness and physical parameters of the anisotropic metamaterial slab, as well as the incident angle of the light beam, strongly affect the properties of the lateral shift, and numerical results validate these conclusions. The effect of a lossy metamaterial on the lateral shift is also investigated. A restriction on the thickness of the slab is obtained, which is necessary for the stationary-phase method to remain valid.