Negative refraction

Light at the end of the tunnel“Can visible light ever be manipulated so that it bends the wrong way?” asks Katharine Sanderson in Nature. She suggests that successfully reversing light by making a negative refraction material could open up the possibility of some rather futuristic devices, such as microscope lenses that can resolve objects smaller than the wavelength of light or the much-desired invisibility cloak.

Sanderson reveals that Jennifer Dionne and Henri Lezec, working in Harry Atwater’s group at Caltech have made a material with a negative refractive index for visible light. The findings were announced at Nanometa 2007 in Seefeld, Austria, but are yet to be peer-reviewed for publication.

The only caveat is that Dionne and Lezec have only demonstrated the effect with a two-dimensional system. Does that count as true negative refraction, asks Sanderson? She quotes Atwater as explaining the options of upgrading to 3D: “Atwater envisages stacking a dense array of waveguides on end: “We have not done this yet, but at least this work illustrates the inherent possibility of doing so.”

Let’s hope so, I really fancy one of those invisibility cloaks.