Asymmetric transmission of light through a planar chiral metamaterial

We report that normal incidence transmission of circularly polarized light through lossy anisotropic planar chiral meta-material is asymmetric for opposite directions. The new effect is fundamentally distinct from conventional gyrotropy of bulk chiral media and the Faraday Effect

Giant microwave and optical gyrotropy in bilayered chiral metamaterials

We report on a novel type of artificial material, which exhibits a very strong gyrotropy in the microwave and optical part of the spectrum, the bilayered chiral metamaterial. The specific rotary power of the optical metamaterial exceeds 600°/mm

Nanoimprint lithography for planar chiral photonic meta-materials

Room temperature nanoimprint lithography has successfully been applied to the fabrication of planar chiral photonic meta-materials. For dielectric chiral structures a single layer of thick HSQ was used while for metallic chiral structures a bi-layer technique using PMMA/hydrogen silsequioxane (HSQ) was applied. The polarization conversion capabilities of planar chiral structures imprinted in dielectric materials have experimentally been observed. This indicates that the developed processes in this work have the prospect of manufacturing planar photonic meta media in high volume at low cost

Asymmetric transmission through planar chiral photonic nanostructures

We report the first experimental observation of the intriguing novel phenomenon of asymmetric transmission in the optical part of the spectrum. In some aspects it resembles the non-reciprocal Faraday effect in magnetized media, but crucially does not require the presence of a magnetic field for its observation. It is radically different from conventional gyrotropy of three-dimensional chiral media (optical activity). The effect was observed in anisotropic planar chiral metallic nanostructures patterned on sub-wavelength scale. This excitation of enantiomerically sensitive plasmons in them manifests itself in an asymmetry of total transmission of circularly polarized light (700-1700 nm) propagating in opposite directions, also found numerically. Furthermore, we show that through chiral symmetry breaking, which allows the excitation of enantiomerically sensitive trapped modes, substantial control over the spectral localization of the effect can be achieved

Electron beam lithography for high density meta fish scale operational at optical frequency

This paper reports our recent progress in electron beam lithography for high resolution and highly dense metallic structures such as fish scale on both silicon and quartz. To observe photonic property in optical frequency, the pitch of 500 nm with both linewidth and gap of 50 nm gap in Al is demanded. For reliable lift-off process, adequate undercut in bilayer layer of resists is essential. Three different bilayers, PMMA/LOR, PMMA/copolymer and PMMA/PMMA (with different molecular weights) were compared and the most suitable bilayer was found to be the PMMA/PMMA with a difference in molecular weight between the top and bottom layer. With such a bilayer stack, dense fish scale pattern with minimum linewidth of 50 nm in Al were fabricated for both transparent and reflective configurations. Astonishing optical properties such as magnetic wall and asymmetric propagating waves through the chiral fish scale were observed

Optical magnetic mirror

We report demonstration of an optical magnetic mirror achieved by nanostructuring a metal surface. In contrast to normal mirrors, it inflicts only small change to the phase of a reflected wave, offering intriguing applications

Magnetic mirror on optical frequency

We report demonstration of an optical magnetic mirror achieved by nanostructuring a metal surface. In contrast to normal mirrors, it inflicts only small change to the phase of a reflected wave, offering intriguing applications.<br/