Target illusion by shifting a distance

Opt Express. 2018 Sep 17;26(19):24280-24293. doi: 10.1364/OE.26.024280.

Abstract

A novel homogeneous illusion device with arbitrary polygonal cross section that acts as either invisible cloak or shifting medium has been proposed and designed based on coordinate transformation method. The material parameters of the device are derived and the effectiveness is verified by full-wave simulation. Results show that whether the illusion device acts as invisible cloak or shifting medium depends on a value of shifting distance which is about 2a (ais circum-radius of the outer polygon).When the shifting distance is larger than 2a, the illusion device acts as an invisible cloak, and otherwise it acts as shifting medium. The stealth effect of all kinds of illusion devices are investigated, including identical-size mapped polygonal devices or non-identical size mapped polygonal devices. The results show that the device is a novel interactive cloak and is different from pre-proposed cloaks. The shifting properties of the device are validated by two examples, including moving the target object virtually and generating illusionary image of a line source. The material parameters of the device are homogeneous, which makes it more practicable in reality. It is hoped that our works may open an avenue for designing novel invisible cloaks, and are helpful for speeding up the potential applications of the illusion devices, such as aircraft or military equipment stealth, target objects camouflage or protection.