Latest Issue of Science News


News

Scientists see the one-way light

Nonlinear materials allow directional discrimination of waves

By
6:22pm, April 19, 2011

Normally, a glass window doesn’t care where a ray of light came from. But special kinds of glass or plastic could be a bit pickier.

Nonlinear materials could distinguish between two rays of light coming from opposite directions, say two Italian physicists. Blocking a ray from one direction and allowing in a ray from the other could be useful for making a one-way street for light.

Textbook optics prohibits this kind of directional discrimination. Everyday linear materials are governed by the reciprocity theorem, which says that a beam of light coming from the left will pass through and reflect off a material in the same way as a beam of light coming from the right.

This article is available only to subscribing members. Join SSP today or Log in.

More from Science News