Optical fibers made with high pressure

2016-03-18 14:30:45

More flexible and efficient electronic optical fibers could result from a new chemical technique developed by a research team led by John Badding at Penn State University.


The new technique, which deposits a non-crystalline form of silicon into the long, ultra-thin pores of optical fibers, is the first of such process to use high-pressure chemistry for making well-developed films and wires of this particular kind of silicon semiconductor. 

Hydrogenated amorphous silicon — a noncrystalline form of silicon — is ideal for applications such as solar cells. Hydrogenated amorphous silicon also would be useful for the light-guiding cores of optical fibers, but depositing the silicon compound into an optical fiber, thinner than the width of a human hair, presents a challenge.

"Traditionally, hydrogenated amorphous silicon is created using an expensive laboratory device known as a plasma reactor," Badding said. "Such a reactor begins with a precursor called silane — a silicon-hydrogen compound. Our goal was not only to find a simpler way to create hydrogenated amorphous silicon using silane, but also to use it in the development of an optical fiber.

"Our high-pressure chemistry technique is unique in allowing the silane to decompose into the useful hydrogenated form of amorphous silicon, rather than the much less useful non-hydrogenated form that otherwise would form without a plasma reactor," team leader Pier J. A. Sazio of the University of Southampton in the United Kingdom, said. "Using pressure in this way is very practical because the optical fibers are so small."