Wafer-Thin 'Metalens' Uses Nanotech to Blow Glass Out of the Water

By Rafi Letzter, Staff Writer | January 2, 2018 12:11pm ET

Physics could soon make it possible to replace those bulky, heavy, glass lenses on cameras with wafer-thin "metalenses" — materials microscopically engineered to focus light at a fraction of the weight and size of traditional lensing.

A team from Harvard University's school of engineering has designed a metalens that can focus nearly the entire spectrum of visible light, the researchers reported Jan. 1 in the journal Nature Nanotechnology. Previous metalenses could focus only narrow color wavelengths, or wavelengths outside the visible spectrum. [Rainbow Album: The Many Colors of the Sun]

When light moves through glass, the different wavelengths (colors) that make up the light slow at different rates. This causes their paths through the glass to bend, or diffract, differently, so that they separate. Pass a beam of white light through a prism, and this effect will cause a rainbow to burst out the other end. This presents a challenge to lens makers; a single focusing element will project an image that has colors from red to violet hitting different spots on the film or sensor.

More:
https://www.livescience.com/61311-metalens-visible-light.html?utm_source=notification