Coming soon: Fibre web lenses

Massachusetts Institute of Technology researchers claim to have developed a sophisticated optical system made of mesh-like webs of light-detecting fibres. They have said the fibre constructs have a number of advantages over their lens-based predecessors. They are currently capable of measuring the direction, intensity and phase of light without the lenses, filters or detector arrays that are the classic elements of optical systems such as eyes or cameras.

The human eye, digital and film cameras, and even the Hubble space telescope rely on lenses and detector surfaces (like the retina) to create images. But while these systems deliver excellent images, they are constrained by their size, weight, fragility and limited field of view. Fibre webs on the other hand are flexible and lightweight. Also a fibre web in the shape of a sphere can sense the entire volume of space around it, they said.

"When you're looking at something with your eyes, there's a particular direction you're looking in. The field of view is defined around that direction. Depending on the lens, you may be able to capture a certain field of view around that direction, but that's it. Until now, most every optical system was limited by an optical axis or direction," said Ayman Abouraddy, a research scientist.

In addition to having an unlimited field of view, the fibre sphere can also detect the direction of incoming light. Light enters the transparent sphere at one point and exits at another, providing a directional reference back to the light source. Researchers opine that the new system will be capable of much more, and potential applications might range from improved space telescopes to clothing that provides situational awareness to soldiers or even the visually impaired.

The transparent fibre-webs could even enable huge computer screens to be activated with beams of light instead of the touch of a finger.

"We could use light to enhance interaction with computers and even gaming systems. It's intriguing--the idea of touching with light," said Professor Yoel Fink of the Department of Materials Science and Engineering and the Research Lab of Electronics, leader of the team.

The findings appear in the June 25 online edition of Nature Materials.