HOME

Designer landscape of localized light in the shape of an elephant. Guided light is molded by bouncing back and forth between two mode converters. Credit: Second Bay Studios/Harvard SEAS

There are many types of light—some visible and some invisible to the human eye. For example, our eyes and brain don't have the tools to process ultraviolet light when it hits our eyes, making it invisible. But there is another type of light that is invisible simply because it never reaches our eyes. When light hits certain surfaces, part of it sticks and remains behind rather than being transmitted or scattered away. This type of light is called near-field light.

Today, near-field light is mostly used for ultra-high-resolution microscopy, known as the near-field scanning optical microscopes (NSOM). However, near-field light also has untapped potential for particle manipulation, sensing, and optical communications. But since near-field light doesn't reach our eyes like far-field light does, researchers haven't developed a comprehensive toolkit to harness and manipulate the near field.

"Today, we have a lot of tools and techniques to design what far-field light looks like," said Vincent Ginis, a visiting professor at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). "We have lenses, telescopes, prisms and holograms. All these things enable us to sculpt freely propagating light in space."