  Based on boundary condition and dispersion relation, the superluminal group
velocity in an anisotropic metamaterial (AMM) is investigated. The superluminal
propagation is induced by the hyperbolic dispersion relation associated with
the AMM. It is shown that a modulated Gaussian beam exhibits a superluminal
group velocity which depends on the choice of incident angles and optical axis
angles. The superluminal propagation does not violate the theory of special
relativity because the group velocity is the velocity of the peak of the
localized wave packet which does not carry information. It is proposed that a
triglycine sulfate (TGS) crystal can be designed and the superluminal group
velocity can be measured experimentally.
