左手材料-負(fù)折射率材料-預(yù)覽頁
【正文】 方向會(huì)主要順著 v的方向 ， 但 kr 方向分量則在一般介質(zhì)與左手材料中恰好會(huì)完全相反 。 ?19961999年 ， Pendry等人相繼提出了用周期性排列的 金屬條和開口金屬諧振環(huán) (SplitRing Resonator)可以在微波波段產(chǎn)生負(fù)等效介電常數(shù)和負(fù)等效磁導(dǎo)率 。 Shelby R. ,Smith . ,et al ,Science ,2021,292,77 負(fù)折射率的應(yīng)用發(fā)展前景 負(fù)折射率材料可以用于平板透鏡 ， 光束控制 ， 耦合器等方面 。目前還只能在微波區(qū)段實(shí)現(xiàn)負(fù)折射率 ， 而且頻率范圍很窄 。 在一定條件下 ， 它也可以表現(xiàn)出負(fù)折射率的現(xiàn)象 。 Fig 5. (A) A negative index metamaterial formed by SRRs and wires deposited on opposite sides lithographically on standard circuit board. The height of the structure is 1 cm. (B) The power detected as a function of angle in a Snell’s law experiment performed on a Teflon sample (blue curve) and a negative index sample (red curve). Shelby R. ,Smith . ,et al ,Science ,2021,292,77 Fig 6. Unit cell of the 901 HWD structure. The direction of propagation of the electromagic field is along the x axis, the electric field is oriented along the z axis, and the magic field is along the y axis. C= cm, D= cm, G= cm, H= cm, L= cm, S= cm, T= 104 cm, W= cm, and V= cm. Fig 7. Schematic of the setup used in the Snell’s law experiment showing the conical horn, lens, sample, and waveguide detector. The measurements were made in the focused and collimated mode at 33 and 66 cm away from the sample. Parazzoli C. G. ,Greegor R. B. ,et al , Phys. Rev. Lett. ,2021,90,107401 Fig 8. Surface plot of measured normalized Ez(r,f ). Refracted peaks :by Teflon at 176。
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