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This Defense Intelligence Reference Document from the Defense Intelligence Agency, dated 6 April 2010, reviews electromagnetic and optical metamaterials for aerospace use. It was produced in FY 2009 under the Advanced Aerospace Weapon System Applications (AAWSA) Program. The report covers super-lenses and hyper-lenses for imaging objects smaller than the diffraction limit, slowing light to shrink components, energy-harvesting absorbers, and one-way chiral devices. It concludes that metamaterials matter for aerospace because they allow smaller, lighter components.
UNCLASSIFIED/ CFQA €Uii&l6ilia ■ !155 0111 Y, Note that the hyper-lens concept does not require employing a bulky near-field scanning optical microscope. However, the practical implementation of the hyper-lens is by no means simple. The original implementation required depositing the sample on the curved surface of the hyper-lens. A more practical implementation of the super-lens has been theoretically proposed by another group (Reference 26). The concept is shown in Figure 8. The hyper-lens involves an array of thin metallic wires converging towards the tip. As is demonstrated, a dense array of metal wires separated by much less than the wavelength constitutes a metamaterial with the indefinite permittivity tensor. Specifically, the tensor component along the wires is given by: (3) where the z component is along the wires and perpendicular direction is normal to the wires. Because the only propagating waves are the TEM waves satisfying the al= k;c 1 dispersion relation, this meta-medium is strongly anisotropic and supports sub-wavelength waves which perform imaging. The spatial resolution is given by the spacing between wires. Figure 8 (right panel) shows the magnified image of a small (A/25) object placed at the tip of the hyper-lens. The magnification factor is Sx. 5 30 .,. 4: ;25 .. ~: 20. 2 15- 1' 0 0..I 10- .. .. > -1 • 5., -2 0 -3 -5-. -4 .5 -10. -5 0 XiL0 5 -5 -5 5 Figure 8. Hyper-Lens Based on a Converging Array of Metal Wires. A small object can be placed at the tip, illuminated from the top, and magnified by the expanding array of wires. Left panel: schematic. Right panel: l\/25 object magnified by a factor sx by the expanding hyper-lens. This hyper-lens can operate at mid-IR frequencies. (Reference 26) Another concept for sub-wavelength imaging employing metamaterials is the so-called Far-Field Super-Lens (FSL). The concept is pioneered in Reference 27. The idea is 10 UNCLASSIFIED,'pliiQlil QSSJCJIP 1155 AN! X
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Report, from the dia collection. The PDF is mirrored here; the original link is above. 27 pages are in the text index: search them above, or from the library's search.