SCIENCE - New Way To Filter Light — First Directional Selectivity For Light Waves Achieved By Researchers

An entirely new way to filter light, one that has long been sought but until now remained elusive, has been achieved by researchers at MIT.For the first time, it’s become possible to selectively filter light according to its direction of propagation — in other words, to filter it based on where it’s coming from.In this photo of the angular-selective sample (the rectangular region), a beam of white light passes through as if the sample was t ...

http://cleantechnica.com/2014/03/29/new-way-filter-light-first-directi