Fiber optics boosted by crystalline core

March 01, 2011 // By R. Colin Johnson
Researchers at Pennsylvania State University last week demonstrated what they said are the world's first optical fibers to harbor a compound semiconductor core.

The Penn State researchers, led by professor John Badding, demonstrated fiber optic cables with zinc-selenide cores, which they claim have a wider wavelength range and superior photonic qualities to the amorphous core fibers in use today.

"The key advantage is that these fibers operate over a wide wavelength range, specifically into the long IR and, just as importantly, that one can exploit the materials properties of crystalline compound semiconductors," said Badding

According to Badding, using optical fibers with a compound semiconductor core enabled them to perform many of the same amplification and waveguide functions that today are being demonstrated on optical chips, but were impossible for traditional optical fibers with amorphous cores.

"Crystalline compound semiconductors can host transition-metal gain media, which amorphous semiconductors cannot," said Badding. "The fiber cores can also be made smoother and more symmetric than competing planar compound semiconductor waveguides, potentially giving them superior wave-guiding properties."

Application of the new optical fibers, which can work with wavelengths as long as 15 microns, will range from more versatile radar and better countermeasure lasers for the military, to improved medical lasers or surgeons, to better environmental sensors to measure pollutants or to detect the release of chemical agents by terrorists.

Badding performed the work with doctoral candidate Justin Sparks and in collaboration with fellow professors Rongrui He, Mahesh Krishnamurthi, Venkatraman Gopalan along with Pier Sazio, Anna Peacock, and Noel Healy of the Optoelectronics Research Centre at the University of Southampton. Funding was provided by the National Science Foundation, and the Penn State Univerity Materials Research Science and Engineering Center.