Two IEEE members were among the MacArthur Fellows named to the 2010 class. Commonly called the "genius awards," the fellowships honor "talented individuals who have shown extraordinary originality and dedication in their creative pursuits and a marked capacity for self-direction." The recipients—Michal Lipson and Dawn Song—each receive a US $500 000 no-strings grant during the next five years. The fellowships are awarded by the John D. and Catherine T. MacArthur Foundation.
Optics for Next-Generation Devices
"Are you sitting down?" That was the first question the representative from the MacArthur Foundation asked Lipson [right], an IEEE senior member, when she got the call last year letting her know she had been named a MacArthur Fellow. "It was a complete surprise," Lipson says. "I honestly thought it was a prank."
Lipson is an associate professor and founder of the Nanophotonics Group at Cornell University, in Ithaca, N.Y. She received the grant for her pioneering work in micrometer-size photonic silicon structures, which have become the building blocks for applications such as on-chip networking, routing, switching, and signal detection. Her research could lead the way to practical optical computer devices that are compatible with current microelectronics.
Much of Lipson's work focuses on developing optics for the next generation of computers and other devices while using low levels of power and remaining compatible with today's electronic workhorse, complementary metal oxide semiconductors (CMOS). "The idea is that if we use photonics to replace electrons with light, not for doing computation but for propagation of data from one side of a chip to another, it will increase their speed and processing capacity dramatically," she says.
Lipson's work in refining optoelectronic and optical circuits has decreased their size, increased their efficiency, and accelerated their switching speeds. The resulting silicon- based photonic ICs have the potential to dramatically improve signal transmission and processing.
Traditionally, optical devices have used optical materials such as gallium arsenide or lithium niobate, which are not compatible with CMOS-based microelectronics. Lipson has made breakthroughs in the design of such devices, using silicon-based fabrication methods. She and her research group have shown that ring modulators, or circular waveguides, can serve as switches for light passing through adjacent linear waveguides when the frequency of light going into the modulators is precisely tuned relative to the linear waveguide. Lipson and her group are creating chips that can slow down, enhance, or manipulate light in order to increase efficiency and performance while also reducing chip size. "Slow light" is a research area that would, among other uses, allow a chip to store a light signal, then retrieve it and send it along when it is needed.
Her efforts occasionally have more fanciful applications: Her team's "Cloaking at Optical Frequencies" paper, published in Nature Photonics, made headlines in 2009 for describing how to build a device similar to Harry Potter's famed invisibility cloak; Lipson's was composed of nanometer-size silicon structures rather than magical fibers.
AN EARLY INSPIRATION
Lipson was born in Israel, where her father taught physics at the Technion-Israel Institute of Technology. Her family moved to São Paulo when she was 8 years old, but she returned to Israel to attend the very college where her father had taught.
Lipson went on to earn bachelor's and master's degrees in physics in 1992 and 1994, as well as a Ph.D. in solid-state physics in 1998. She joined MIT as a postdoctoral associate in the materials science department in 1999, where she focused on silicon light emitters, the technology that made integrated optical processing on a nanoscale level possible.
Lipson moved to Cornell in 2001 to become an associate professor in the School of Electrical and Computer Engineering, where she founded the Nanophotonics Group, a research lab devoted to the physics and applications of nanoscale photonic structures. Nanophotonics refers to structures that are about 200 times smaller than a human hair.
As early as 2003, Lipson was publishing work showing that one of the first applications of nanophotonic circuits would be routers and repeaters for fiber-optic communication systems, research that quickly made the technology practical for home use.
"I think that's what I like about my work—it's applied physics," she says. "You take fundamental principles and apply them to real problems."
The Nanophotonics Group has grown enormously in the last few years. She says the group started "from scratch" with a completely empty lab. "Now it's very large, with 20 Ph.D. students," she says. "It's a very active group."
Throughout her career, Lipson has been active as an IEEE volunteer. She serves on the IEEE Photonics Society advisory board, has been on the advisory board of the IEEE Photonics Journal, and has served as a guest editor for the IEEE Journal of Selected Topics in Quantum Electronics. In addition, she is an active member of the IEEE Women in Engineering group. "As a senior person in my field, I have a responsibility to help other women in engineering," she says.
DRIVE AND DEVOTION
One of the best things about receiving the MacArthur Fellowship, Lipson says, is that her two sons, ages 6 and 13, finally understand what she does. "And they understand the importance of what I do, and how my success is all self-driven," she says. "If you're not excited about your work, no one else is going to get excited. This is a very competitive field, and there's not a lot of funding. Everyone is competing for the same pot of money."
The MacArthur grant will allow her team to do work that might not have immediate commercial application. "I want to add to my efforts and do some research that is a little more fundamental and harder to get funding for," she says. For example, she has started working on a project using photonics to simulate a black hole. The new project has a bonus for her: Her partner is her father, Reuven Opher, who is on leave from the University of São Paulo to work as a visiting scientist at Cornell.
Lipson says she was inspired to study physics because of her father's passion for the field. "He loves what he does. He gave me and my twin sister a great lesson: There is nothing more beautiful in this world than the fact that we can make an impact through science—and get paid for it," she says, laughing.
Seeking Beauty in Computer Security
Is there something captivating in computer code? IEEE Member Dawn Song [right] contends there is.
"To me, life is about creating something truly beautiful, and I think there's a lot of beauty in science and engineering, beyond what people usually associate with the word beauty," Song says. "An elegant idea that solves a hard problem is to me—and I think to many others—something very beautiful."
Song was named a MacArthur Fellow for her work on computer security for software, hardware, and networks. She is an associate professor in the department of electrical engineering and computer science at the University of California, Berkeley.
A CHANGING FIELD
One of her main interests is developing technologies to analyze the security-related properties of program executables, extract the root cause of attacks, and build defenses against them.
Song's work in this area began in early 2000, when she was researching how to defend systems against malicious code as an assistant professor at Carnegie Mellon University, in Pittsburgh.
"For the first time, we were seeing Internet worms on a large scale," she says. At the time, most approaches to defending against such attacks involved looking for the symptoms, such as increased network traffic or anomalous signals, and trying to fight the problems that arose.
"That was effective in some cases, but it didn't help us understand what the problem really was," she says. She started considering how to preempt the attacks by, for example, uncovering vulnerabilities that worms could exploit. That way, security experts could "automatically generate defenses against the attacks, even when they morph," she says.
Song and her research group developed the BitBlaze binary analysis infrastructure, a suite of technologies to look deep inside the program executables—either benign but vulnerable programs or malicious code—and defend against malicious attacks.
By the time Song moved to UC Berkeley in 2007, the Web had grown, which meant additional security challenges. To address them, she started a sister project, WebBlaze, "to design and develop new technologies to enhance security in the Web space," she says.
Song's WebBlaze research group has developed tools for finding new classes of vulnerabilities in browsers and applications and has devised defenses against them. Some of the approaches have been adopted in industrial standards and mainstream browsers.
FROM PHYSICS TO SECURITY
Born in China, Song went on to receive a bachelor's degree in physics from Tsinghua University, in Beijing, in 1996. She was drawn to the field because "physics is the language of nature," Song says.
"You can really see the beauty in it. I think studying physics offered me great training."
Song began studying for a Ph.D. in physics at Cornell University, in Ithaca, N.Y. She had become intrigued by computer science, so while at Cornell she took a few classes and did some research projects. "I realized I was really interested in computer science research and decided to switch," she says.
After a year at Cornell, she transferred to the computer science Ph.D. program at Carnegie Mellon, where she obtained a master's degree in 1999. She moved to UC Berkeley to finish her Ph.D., which she received in 2002.
"I chose to work in computer security because I was fascinated by the problems and saw how important it would become in the future," Song says.
After graduating from UC Berkeley, she worked as an assistant professor in electrical computer engineering and computer science at Carnegie Mellon for five years. She returned to Berkeley to become an associate professor in computer science in 2007 and received tenure last year.
Looking ahead, Song plans to develop tools to protect users' information and privacy on social networks and in the cloud.
"Technology is doing good by making people more connected and making society more open," she says, "but in many cases, people would like to protect their privacy. We are developing technology to do just that."
Song is also extending the BitBlaze approach to improve security in networked medical devices and embedded systems.
The MacArthur grant will allow her to explore other areas of computer security and computer science, she says, although she has not determined the nature of those ventures. "The grant will be of great help in enabling me to do work that I otherwise may not be able to do," she notes.
Song says she never wants to stop exploring new ideas: "From China to the United States, from physics to computer science, I always enjoy getting into new environments and new areas, because they propel my learning."