Clever cloaks: Unique metamaterials preserve phase while guiding surface waves around ultrasharp corners and bumps
(Phys.org)—Today's photonic and plasmonic devices – the latter based on surface plasmons (a coherent delocalized electron oscillations that exist at the interface between metal and dielectric) and combining the small size and manufacturability of electronics with the high speeds of optics – need the ability to guide surface electromagnetic waves around disorder, such as ultrasharp corners and bumps, without disturbing the wave amplitude or phase. That being said, achieving this preservation of phase and amplitude has been difficult due to the fact that light momentum must be conserved in a scattering event (that is, when electromagnetic radiation or particles are deflected or diffused by localized non-uniformities in the medium through which that radiation is passing). However, scientists at Zhejiang University in Hangzhou, China, Nanyang Technological University, Singapore, and Massachusetts Institute of Technology created (so-called invisibility) cloaks based on specifically-designed nonmagnetic anisotropic, or directionally dependent, metamaterials that achieve nearly ideal transmission...