From a flat mirror, designer light
Exploiting a novel technique called phase discontinuity, researchers at the Harvard School of Engineering and Applied Sciences (SEAS) have induced light rays to behave in a way that defies the centuries-old laws of reflection and refraction. The discovery, published Sept. 2 in the journal Science, has led to a reformulation of the mathematical laws that predict the path of a ray of light bouncing off a surface or traveling from one medium into another — for example, from air into glass. “Using designer surfaces, we’ve created the effects of a fun-house mirror on a flat plane,” said co-principal investigator Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS. “Our discovery carries optics into new territory and opens the door to exciting developments in photonics technology.” It has been recognized since ancient times that light travels at different speeds through different media. Reflection...