Researchers at the Hong-Kong university of Science and Technology have proposed a theory which can make one object look like another. The idea is to use the concepts of complementary media and transformation optics to generate a general illusion.
First, the object is optically canceled by using a complementary material. A complementary material is one in which the values of permittivity and permeability are complementary to the values in the nearby region of space containing the object. This complementary material cancels out the effect of this object on the plane wave, making it optically invisible.
Then using a transformational material, this plane wave is again distorted in a way that the ‘object of choice’ would. Therefore, anybody looking at this object would see the ‘object of choice’ instead.
Using these concepts, an Illusion Device can be designed which can transform the scattered light outside a virtual boundary into that of the second (illusion) object, regardless of the profile and the direction of the incident light thereby creating a stereoscopic illusion for any observer outside the virtual boundary.
(a)The man (the object) and the illusion device in real space. (b)The woman (the illusion) in the illusion space. (c)The physical description of the system in real space.
The illusion device is composed of two parts, the complementary medium (region 2) that optically“cancels” a piece of space including the man (region 3), and the restoring medium (region 1) that restores a piece of the illusion space including the illusion (region 4 in (d)).Both real and illusion spaces share the same virtual boundary (dashed curves).