New Process Builds Electronics Into Optical Fiber

Advance could lead to building a range of devices inside tiny light transmitters

March 16, 2006

Scientists from Pennsylvania State University and the University of Southampton in the United Kingdom have demonstrated a new way to combine microelectronics and optical fibers--a development that opens up potential applications in fields as diverse as medicine, computing and remote sensing.

A wire-packed glass fiber passes through the eye of a needle.

As they explain in the March 17 edition of the journal Science, the researchers have discovered how to fashion a thin, flexible tube of ultra-clear glass--an optical fiber--that has a hollow core packed with microscopic wires made of a semiconductor such as germanium. The scientists then created solid-state electronic devices, including a transistor, inside the semiconductors.

"This advance is the basis for a technology that could build a large range of devices inside an optical fiber," says Penn State chemist John Badding, one of the lead authors of the report.

Indeed, he says, it could help meet one of the greatest challenges in modern information technology. How do you rapidly and efficiently exchange information between optical fibers, which have proved to be the ideal medium for transmitting data (in the form of light pulses), and solid-state microelectronic devices, which are by far the most effective tools for manipulating and processing the data? "If the signal never leaves the fiber, then it is faster, cheaper and more efficient," says Badding.

"This fusion of two separate technologies opens the possibility of true optoelectronic devices that do not require conversion between optical and electronic signals," says University of Southampton optoelectronics expert Pier Sazio, another lead author. "If you think of the fiber as a water main, this structure places the pumping station inside the pipe. The glass fiber provides the transmission and the semiconductor provides the function."

Support for this research came from the National Science Foundation; the NSF-funded Penn State Center for Nanoscale Science; the Penn State-Lehigh Center for Optical Technologies; the U.K. Engineering and Physical Sciences Research Council; and the Mexican Council for Science and Technology.