Research Highlights

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  • Physics

Published online: 8 July 2009 | doi:10.1038/nchina.2009.141

Optics: Swap trick

Felix Cheung

Introduction

© (2009) APS

Transformation optics, the use of novel materials to bend light in seemingly impossible directions, has generated enormous interest in the scientific community with the promise of a host of futuristic gadgets such as the 'cloak of invisibility' and the 'invisible wall' (see Optical devices: Window replacement). Che Ting Chan, Zhaoqing Zhang and co-workers at the Hong Kong University of Science and Technology¹ have now come up with another radical idea for the use of transformation optics — to make a real object appear like a different illusory object of your choice.

Although the theory behind their concept is complex, the general idea is simple: use an 'illusion device' to scatter light as if from the illusory object to disguise the light scattered from the real object.

The researchers conducted wave simulations to show how plane waves are scattered off a plastic spoon (see top image) and a metallic cup (see bottom image). They compared the scattering patterns to that of a spoon placed beside an illusion device (see middle image). The illusion device transformed practically all of the scattered light around the spoon into that around the cup — to an observer standing at a distance, the spoon would indeed appear to be a cup.

The researchers acknowledge that although their principle looks good on paper, considerable effort will be required in practice to overcome many issues and technological challenges. Only time will tell if their idea will become reality or remain just an illusion.

The authors of this work are from:
Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China

Reference

1. Lai, Y. et al. Illusion optics: The optical transformation of an object into another object. Phys. Rev. Lett. doi:10.1103/PhysRevLett.102.253902 (2009). | Article |