Researchers at the Karlsruhe Institute of Technology in Germany, working in the new field of transformation optics, have created an invisibility cloak that could lead to more efficient solar cells. The researchers have been able to manipulate a beam of light — a red light at a wavelength of 700 nanometers — to actually make something visually disappear. This isn’t all about making things disappear, however, the new technology’s biggest promise is in the refraction of light — which will help scientists concentrate solar rays into more efficient solar energy technology.

Though the current cloak the researchers are working with is tiny — only half the width of a human hair — it could mean huge things for the optical world. Researchers achieved their breakthrough by laser writing into a polymer material a 3-D pattern that looks a lot like a wood pile — the researchers actually refer to it as “logs” — which a light beam is then passed through.
When the light passes through the polymer, the 3-D pattern — which has logs of varying thickness — bends the light in ways never achieved before, which creates the illusion of invisibility. Researchers believe that if they could increase the resolution of their 3-D laser tools in order to decrease the size of their logs they could make a cloak that could work for the entire light spectrum — not just red light waves of a wavelength of 700 nanometers. That would allow them to develop an optical “black hole” which could increase the concentrated light in a solar cell — thereby increasing its efficiency. How about Harry Potter and The Invisible Solar Cell — maybe the series hasn’t ended after all.
Via Science Daily