ArticleCao T, Zou Y, Adawi AM, Cryan MJ.
Opt Express. 2014 Sep 22;22(19):22699-706.
We numerically demonstrate an impedance-matched multilayer stacked fishnet metamaterial that has zero index with flat high transmittance from 600 nm to 620 nm. The effective refractive index(n(eff)) is calculated to be -0.045 + 0.466 i and the normalize effective impedance(Z(eff)/Z(0)) is 0.956-0.368 i at 610 nm. The light emitted by a red conjugated polymer layer embedded in such a zero index metamaterial (ZIM) is concentrated in a narrow cone in the surrounding media, where the half-power beam width (HPBW) of the center lobe of the radiation pattern is around 25° in the wavelength range between 600 nm and 620 nm, giving directive emission in the visible region. This proposed light focusing system can be applied to sensing, beam collimating and filtering functionalities.