Zinc selenide

There has been a significant breakthrough in the field of fiber optics. Researchers led by Prof. John Badding at Pen State University have developed a new type of fiber optic cable that uses zinc selenide instead of the traditional silica (otherwise known as glass).

Currently, fiber lines link continents together and provide the backbone for data transfer across the globe. The tiny conduits are able to send data at speeds from 10Gbps to 40Gbps (that’s gigabytes per second) while being the width of a human hair. The current technology has its shortcomings, however. Glass is notoriously hard to work with, hard to splice (data loss occurs at splice points), and there are other complications — the light at the edge of the fiber travels at a different speed than the light at its core.

The new zinc selenide fiber may overcome many of these limitations. The difference lies in the arrangement of atoms, says Badding in an article for phsyorg.com. “Glass has a haphazard arrangement of atoms; in contrast, a crystalline substance like zinc selenide is highly ordered.” This allows light to be transmitted over longer wavelengths, specifically those in mid infra-red.

Zinc selenide is a semiconductor, and while long known to have many characteristics favorable for fiber optic data transfer, it has been too hard to work with. That is until a graduate student developed a new way of working the material into a fiber optic cable. “Using an innovative high-pressure chemical-deposition technique developed by Justin Sparks, a graduate student in the department of chemistry, Badding and his team deposited zinc selenide waveguiding cores inside of silica glass capillaries to form the new class of optical fibers. ‘The high-pressure deposition is unique in allowing formation of such long, thin, zinc selenide fiber cores in a very confined space,’ Badding said.”

The new cables have two important characteristics. First of all, they are able to more efficiently convert light from one color to another, something that traditional fiber had difficulties doing. The second important feature of these new cables is that they can transmit data using radiation that lies outside of the visible spectrum. The cables can do the aforementioned infra-red that traditional modes of transmission are wholly incapable of doing, opening up new options for fiber optics.