Ideal-lens cloaks and new cloaking strategies

Abstract

Previously [Courtial et al., Opt. Express 26, 17872 (2018)] we presented the theory of transformation optics (TO) with ideal lenses and demonstrated an example, an omnidirectional lens. Here we interpret this omnidirectional lens in two different parameter regimes as ideal-lens cloaks that employ different cloaking strategies: a standard "shrink cloak" in which objects appear smaller (ideally zero) and a novel "abyss cloak" in which interior physical-space positions are mapped to the exterior and thus are visible only from certain directions. We proceed to combine two nested abyss cloaks into another novel, omnidirectional, "bi-abyss cloak." Our work significantly extends the arsenal of cloaking strategies.

Supplementary document for Optical simulation of curved spaces - 4351338.pdf

“…Ideal thin lenses cannot be realised physically, but they can be useful in the initial design of instruments comprising physical lenses. Combinations of skew lenses are rarely used, but theoretical studies of structures comprising skew ideal lenses have uncovered interesting possibilities; for example, such structures can form transformationoptics devices [5], including omnidirectional cloaks [6].…”

Perfect invisibility with nested inside-out cloaks

“…al.,. 1 We will employ the so-called Abyss Cloak, which works by shifting the image of the cloaked physical object to an exterior position. This means that the exterior image is only visible along the lines of sight that intersect both the image and the cloak, thus making the cloaked object invisible from other directions.…”

Axicon cloak: broadband field of view invisibility for a visible light

“…design "proper" TO devices (working for a visible light and all viewing positions and directions), using standard optical elements like lenses. We proposed theoretically several ideal-lens devices, 11,12 but realised that these structures require the included lenses to work strongly non-paraxially for them to work well (the real-life lenses, of course, work well only in a paraxial regime). At this point, we arrived to a compromise we initially wanted to overcome: we suggested to replace the ideal lenses with lens holograms, optimised for one viewing position.…”