"The biggest difference is that electrons cannot travel as fast as photons. In this world, there is nothing that can travel faster than light."
Associate professor of electrical engineering
Anyone who has stared impatiently at a computer screen, waiting for a web page to load, knows that speed is everything on the Internet. Thanks to fiber optics, web navigation has gotten exponentially faster since the days of dial-up modems.
Fiber optic communication systems are one application of photonics -- the science of light that is in many ways the successor to electronics. Associate Professor of Electrical Engineering Jie Lin explains the difference. "In electronics, people try to manipulate electrons," she says. "In photonics people try to manipulate photons."
Jie says the field of photonics excites her because, though electrons and photons behave similarly, photons -- packets of light -- have a couple of advantages. "The biggest difference is that electrons cannot travel as fast as photons," Lin says. "In this world, there is nothing that can travel faster than light," she says.
In her research, Lin focuses in particular on the creation of integrated circuits for optoelectronics devices. Just as electronics shrank dramatically in size once integrated circuits were developed, similar integrated circuits for optoelectronics devices can make it possible for those devices to be produced in smaller and smaller versions -- picture cell phones the size of briefcases compared to the compact models we know today.
She is also collaborating with colleagues in Switzerland on another application of photonics. A single optic fiber laid along the entire length of a buried pipeline could enable an oil company to monitor the status of the pipeline and detect leaks, or changes in pressure or temperature. Similar systems can keep an eye on security in large buildings. Such distributed sensors can already pinpoint the location of issues to within five or 10 centimeters. Lin is modeling the theoretical limits of the systems to guide the future sensors design.
As a teacher, Lin relates to the students who learn best by "messing around" with things. She assigns open-ended projects in which students have to generate their own ideas for how to apply the principles learned in class.
"Every time my course evaluations come back, the students say, 'I love the projects.' Even though I assign them projects that keep them up for several nights," she says. "They love it!"
Posted Sept. 20, 2011