Metamaterial-based planar THz sources

Summary form only given.Double negative metamaterial (DNM) is a new type of artificial electromagnetic material with the real parts of both effective permittivity and permeability being negative. It exhibits unique properties such as negative index of refraction, reversed Cherenkov radiation (RCR), and reversed Doppler effect. Based on the new RCR, we have developed a novel metamaterial-based planar terahertz (THz) source^{1, 2}. In order to improve its output power, we make use of a sheet electron beam³ instead of single electron. The metamaterial-based planar THz source has some attractive advantages over the traditional vacuum electron devices such as miniaturization due to the sub-wavelength property and an enhanced transmission due to resonant effects. However, there exists a serious challenge: how to design, characterize, and fabricate the DNM. In this paper, we discuss this issue in details and explore feasible methods to solve it.