Moving targets virtually via composite optical transformation.

We propose a composite optical transformation to design an illusion device which can move the image of a target from one place to another place. Enclosed by such an illusion device, an arbitrary object located at one place appears to be at another place virtually. Different from the published shifted-position cloak which is composed of the left-handed materials with simultaneously negative permittivity and permeability, the illusion device proposed in this paper has positive permittivity and permeability. Hence the proposed illusion device is easier to be realized by artificial metamaterials.