Abstract-Experimental demonstration of a magnifying prism hyperlens at THz frequencies

 Md. Samiul Habib,  Alessio Stefani,  Atakaramians, Simon C. Fleming, Alexander Argyros, Boris T. Kuhlmey

http://ieeexplore.ieee.org/document/8107865/references

We experimentally demonstrate a magnifying wire medium (WM) prism hyperlens at THz frequencies. The different lengths of wire in the prism have different resonance frequencies, so that there is no frequency at which a good image is possible. We show that using spatially varying time gating or frequency convolution the resonant response can be removed and experimentally demonstrate sub-diffraction magnified imaging of a sub-wavelength double aperture.

Abstract-Metamaterial fibres for subdiffraction imaging and focusing at terahertz frequencies over optically long distances

• Alessandro Tuniz,
• Korbinian J. Kaltenecker,
• Bernd M. Fischer,
• Markus Walther,
• Simon C. Fleming,
• Alexander Argyros
• & Boris T. Kuhlmey

• http://www.nature.com/ncomms/2013/131028/ncomms3706/full/ncomms3706.html

Using conventional materials, the resolution of focusing and imaging devices is limited by diffraction to about half the wavelength of light, as high spatial frequencies do not propagate in isotropic materials. Wire array metamaterials, because of their extreme anisotropy, can beat this limit; however, focusing with these has only been demonstrated up to microwave frequencies and using propagation over a few wavelengths only. Here we show that the principle can be scaled to frequencies orders of magnitudes higher and to considerably longer propagation lengths. We demonstrate imaging through straight and tapered wire arrays operating in the terahertz spectrum, with unprecedented propagation of near field information over hundreds of wavelengths and focusing down to 1/28 of the wavelength with a net increase in power density. Applications could include in vivo terahertz-endoscopes with resolution compatible with imaging individual cells.