An optical illusion device making objects longer

Based on transformation optics, we present an optical illusion device, which can transform an arbitrary object virtually into a long-size object in the direction as one desired. Such an illusion device will confuse the detector or the viewer outside the virtually boundary, and hence the real size and material parameters of the imbedded object will not be perceived. To demonstrate the properties of this device, full-wave finite element simulations for the two-dimensional case are performed.