MIT Develops Optical Diode

Researchers at MIT reported progress in developing an optical diode with potential applications in optical circuits on silicon chips. The innovation leverages a form of a material called garnet, which has a different index of refraction. A thin film of the material is deposited on a chip so that light passes only freely only in one direction and is diverted back into a loop if is coming from the other direction. The discovery is seen as a big step for optical circuits. http://web.mit.edu/newsoffice/2011/optical-computing-diode-1123.html