DIRD_07-DIRD_Invisibility_Cloaking-Theory_and_Experiments.pdf

UNCLASSIFIED / ##@=@5Fi-6hi-U6E-ONEY Defense Intelligence Reference Document BS Acquisition Threat Support 2 March 2010 ICOD: 1 December 2009 DIA-08-1003-001 Invisibility Cloaking: Theory and Experiments UNCLASSIFIED / -2@Re@EEE6h-U6GE-Oii

UNCLASSIFIED / #P@R=OEELGH-GE-Shis Invisibility Cloaking: Theory and Experiments Prepared by: (b}(3):10 USC 424 Defense Intelligence Agency Author: (b)(6) Administrative Note COPYRIGHT WARNING: Further dissemination of the photographs in this publication is not authorized. This product is one in a series of advanced technology reports produced in FY 2009 under the Defense Intelligence Agency, [(b)(3):10 USC 424 Advanced Aerospace Weapon System Applications (AAWSA) Program. Comments or questions pertaining to this document should be addressed to , AAWSA Program Manager, Defense Intelligence ead…

UNCLASSIFIED / -#@R-@5FEGH-U6=-6NE Contents INtroduction ...cccccccecsssnecvecsesenanerennenscesarenens sensrerecauees pacadeasnenanazentnenatenstsnscenanenssen anasave Vv CAMOUFLAGE! 20. scseseresuscvevevevesesereseouresusaresevevesusapevevesuvesevesesasesevass veovearurzos pusurereeusesesveen L TFANSPALeNCy oe acareneccnnenenen wanes neacrouscesuecencsecacaneas Acnananouasesasaeen seauseenenseaad wa uaneuanenceenacen 3 CLOAKING oe ccencervsercsnsvonsecerssuvucssuseseravereses evepaseses coe raneveserssenavesesusssenanernreverssucuserepenusnses O Metamiaterrials ........cccencsesesseeeevencnc…

UNCLASSIFIED / $P@R-@EELGEM=V6E-8N Figure 12. Lycurgus Cup (British Museum; AD Fourth Century). c.cccccccscsesensssnrnenes LL Figure 13. Idea for a Cloaking Device for Visible Light ...c.c.cscscssnceevenancnencncnananananes 12 Figure 14. Advances in MetamaterrialS .....cscscssscsssazsesnassennasssocnecnenseensnccsnecrsucesssseers LO Figure 15. Demonstration of Negative Refraction With “Bulk” Optical Metamaterials Made of Nano-Fishmets ........ccccrescecnscanenensnerensneneesnenenenan L4 Figure 16. Demonstration of Negative Refraction With “Bulk” Optical Metamaterials Made of Nanowires. .......…

UNCLASSIFIED / -P@R-@5EEGE-UGE-ONEY Invisibility Cloaking: Theory and Experiments Introduction The idea of invisibility has fascinated peaple for millennia, inspiring many myths, novels, and films. Invisibility cloaking has recently become a subject of science and technology. This paper describes the important current theoretical and experimental developments and tries to project into the future. UNCLASSIFIED / (2@.2- Obeid dG Odes

UNCLASSIFIED / -B@R-@FFEGEH=USE-ONET Camouflage Invisibility may be achieved through three principal methods: camouflage, transparency, and cloaking. Many animals and some plants use camouflage to disguise themselves from predators—for example, by assuming the shapes and colors of objects in their surroundings. The military has long used forms of camouflage; a recent military application of camouflage is stealth technology. Stealth planes have aerodynamically unusual, edgy shapes and are coated with a special material. Both features serve the same purpose: to make the plane “invisible” to rada…

UNCLASSIFIED / SQ. 05Gb SO hey Another recent example of camouflage is optical camouflage, developed by the University of Tokyo’s Tachi Laboratory. Figure 2 shows an example of optical camouflage. A camera captures the background scene behind the person. The image is processed and projected onto the person via a semitransparent mirror. The person wears an “invisibility cloak” made of a retroreflective material that reflects light back in the direction whence it came, like cats-eye-reflectors do. As the cloak carries the projected image of the background, the person seems to disappear, but sure…

UNCLASSIFIED / ABO R-@ErLEGHE-VSE-Si> Transparency H. G. Wells’s novel The Invisible Man represents another strategy for becoming invisible: transparency. In Wells’s novel, the invisible man, a disgruntled college professor, invents a substance that somehow changes the refractive index: of his body. Most transparent substances, like glass, air, or water, modify the speed of light, because the atoms or molecules of these substances absorb and re-emit light, which takes time. The delay caused by the atoms and molecules results in a reduced speed of light and hence in a refractive index larger th…