Superluminal group velocity in an anisotropic metamaterialHailu Luo1, Wei Hu2, Weixing Shu1, Fei Li1 and Zhongzhou Ren1
1 Department of Physics, Nanjing University - Nanjing 210008, PRC
2 Laboratory of Light Transmission Optics, South China Normal University Guangzhou 510630, PRC
received 7 January 2006; accepted in final form 13 April 2006
published online 12 May 2006
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.
78.20.Ci - Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity).
41.20.Jb - Electromagnetic wave propagation; radiowave propagation.
42.25.Gy - Edge and boundary effects; reflection and refraction.
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