Invisibility cloaks closer to living up to their name
...
They found they were able to bend visible light by using a two-dimensional array of coaxial waveguides arranged in a hexagonal configuration. The waveguides were composed of two layers of silver sandwiching a gallium-phosphorus insulator; they could maintain a negative refractive index for light of wavelengths as short as 450-500 nanometers, corresponding to the color blue.
The literal invisibility cloak is stll incomplete—as it stands, the metamaterial described here would be able to bend away every color except violet, so anything "cloaked" would just be highlighted purple. Even if researchers do eventually conquer violet, an invisibility cloak might still be noticeable to the human eye. Still, the ability to bend shorter wavelengths brings scientists a step closer to a new way of beating the diffraction limit and creating superlenses that can see features even smaller than the wavelengths we use.
Nature, 2010. DOI: 10.1038/NMAT2747 (About DOIs).
If they get this working, it's one step closer to me getting my own Klingon Bird of Prey.
