Researchers at Massachusetts Institute of Technology (MIT) have developed a new 400 ìm fiber that emits light along its length. The fiber emits light in all directions and its brightness can be controlled according to the requirement.
A new fiber developed by Yoel Fink's group emits blue laser light only at a precisely controlled location. Photo: Greg Hren
The fiber holds hope for medical tools and three-dimensional displays woven from flexible fibers. It can be used to activate or control medical devices so as to inject or activate therapeutic compounds at specific locations, without affecting healthy tissue. The three-dimensional displays woven from these flexible fibers can also project different data to the left and right eyes.
The fiber consists of a hollow core surrounded with multiple layers of materials with dissimilar optical properties. This leads to a mirror effect. The core contains a movable droplet of fluid. When laser is used to pump the droplet it receives energy and emits light. This light bounces repeatedly between the mirrors and comes out as a 360° laser beam.
Four liquid-crystal channels surround the fiber core and two electrode channels are used for controlling these liquid-crystal channels. The researchers studied a hypothetical application that will enable the same image of a transparent, woven display to be viewed on both sides. They activated liquid crystals located on opposite sides of the fiber. And in principle, a fiber can possess numerous liquid-crystal channels that can change the intensity of light in various directions. Each fiber provides a single image pixel and this is a disadvantage.
The fiber research was conducted by seven researchers, including director of MIT’s Research Laboratory of Electronics (RLE), Yoel Fink; Francis Wright Davis Professor of Physics, John Joannopoulos; research student and lead author, Alexander Stolyarov; and postdoc, Lei Wei.
The National Science Foundation and the U.S. Army provided funds for the research through Center for Materials Science and Engineering and the Institute for Soldier Nanotechnologies at MIT.