(20) Lei Zhou
Fudan University, China.

Title: Manipulate light propagations and polarizations through meta-materials

Abstract:

Meta-materials are artificial electromagnetic (EM) materials composed by subwavelength local resonance structures of electric and/or magnetic type, and thus possess arbitrary values of permittivity and permeability dictated by such resonance structures. Many novel EM properties, such as the negative refraction and the superlensing effect, were predicted or discovered based on meta-materials. In this talk, we review our recent efforts in understanding the exotic EM properties of meta-materials, and employing such novel materials to manipulate the light propagations and polarizations. We will first show how to manipulate EM wave polarizations by using meta-materials at both microwave and optical frequencies, including a complete polarization conversion, arbitrary rotations of polarization angle (Faraday-like effects), etc. We also show how to manipulate EM wave transmissions through several classically opaque media, including a negative-permittivity slab (such as a metal) and a subwavelength waveguide at cutoff, and make them transparent at certain frequencies with the help of metamaterials. We finally show how to design a plasmonic metamaterial based on fractal geometry and present our recent theoretical and experimental results of employing such a plasmonic metamaterial to focus near field sources.

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