LAUSR

Development of continuous wave (CW) sources has recently advanced in various frequencies of the terahertz waveband. However, there are few materials suitable for the terahertz waveband, and attractive materials are eagerly awaited. Metamaterials with artificial sub-wavelength structures would enable designs with an arbitrary refractive index including negative values providing simultaneous control of dielectric and magnetic properties. Here, measurements demonstrate that a simple metasurface, a two-dimensional metamaterial, consisting of asymmetrical metal patches on the front and back of a dielectric substrate has a negative refractive index of −3.03 + j0.29, transmission of 56.4%, and reflection of 3.51% at 1.96 THz. The metasurface would offer attractive optical components such as super lenses, ultrathin collimators, and cloaking.