By Sam Scott
Before she became one of the first scientists to bend light back-ward,
or a member of the Stanford fac-ulty at 28, or a listing on Oprah’s “50 things that will make you say ‘Wow!’ ” Jennifer Dionne was already someone nearly every-one expected to make a mark. How was less clear.
Her counselor at Bay View Academy, a Catholic girls’ school in Riverside, R.I., had her pegged as an astronaut. Her religion instructor recalls the natural teacher. Her classmates, though, were apparently of two minds,
judging by the senior superlatives bestowed her way: Dionne was “Most Likely to be a CEO” and “Most Likely to Buy the Brooklyn Bridge.”
CEO was a natural enough prospect for a super-involved math whiz. But the bridge? She first thought it was a prediction she’d be rich enough to pay for the famous span. “Of course, later on, I realized I’m just gullible.”
Not surprisingly, nobody guessed she would become a rising star in the growing, often fantastical world of nanophotonics, a discipline that’s rewriting the textbooks on how light and substance interact on dimensions measuring just atoms across. In 1999, the field hardly trip-ped off the tongues of many scientists, let alone those of high school students.
Dionne led the first experiment to show visible light bending backward in contradiction of hundreds of years of scientific understanding.
Today, Dionne’s accomplishments range from fundamental discoveries in physics, such as how quantum mechanics governs light at the nanoscale, to research with implications that sound like sci-fi. Her work designing synthetic substances — metamaterials — exactingly patterned to steer light in bizarre ways has raised hopes for one particularly sensational application, invisibility cloaks.
In fact, such cloaks may be just a decade away, Dionne says, though she’s not going to be pushing the research in that direction. Her mantra is essentially the opposite: to make the invisible visible. And that turns out to be a pursuit with no shortage of applications.
Since arriving at Stanford in 2010, Dionne has led her lab to design mater-ials that are capable of converting weak — and invisible — infrared sunlight into harvestable energy. The group has developed optical tweezers that shrink light into focused beams that can trap objects as small as proteins. And she has invented techniques to watch the unfolding of minuscule processes, like the absorption of hydrogen atoms into palladium nano-particles, yield-ing insights into energy and information storage.
Perhaps what most excites Dionne is creating windows into areas
now either beyond our scope or visible only through intrusive means. Human tissue, for example, is transparent to near-infrared light — the reason your hand glows when you cup it over a flashlight. Her group
has eyes on developing nanoparticles that could, say, bond with proteins in the brain and then change color in response to neurons fir-ing, creating an easily accessed, ultra- high-resolution map of the brain at work.
Her ultimate goal is to develop windows on any process — biological, chemical or energy conversion — as it happens, at the nanoscale. To do that, she needs to make optical magnification exponentially more powerful. Electron microscopes are strong enough but ill-suited for real-time observation. Among their restrictions, they require most specimens to be in a vacuum. Light magnification makes no such demands — but it’s hundreds of times weaker.
“If you had a microscopic lens that could really give you this vision into processes as occurring at molecular or even atomic-length scales, there are so many applications that could emerge from that,” she says.
It’s a lofty goal, requiring no less than a workable way around the diffraction limit, a fundamental restriction on magnification enforced by the very size of light waves. It’s something perhaps 50 years from realization, she says. But Dionne likes to think big and long-term.
And time is on her side. The 33-year-old assistant professor of materials science and engineering is very much in the early part of her career. Her first grad students just defended their dissertations this spring. Professor Harry Atwater, her adviser at Cal-tech, notes that her odometer is low — there is much to come. But the journey so far has gotten plenty of attention.
In February, she was named one of 126 Sloan Research Fellows, including two others at Stanford. The $50,000 award was the latest in a series of distinctions she has garnered for young brilliance, including a Presidential Early Career Award for Scientists and Engineers — handshake with the president included — and a spot on MIT Technology Review’s annual list of Innovators Under 35.
It’s all well-deserved, according to Matt Sheldon, an assistant professor of chem-istry at Texas A&M, who says befriending Dionne while he was a doctoral student at UC-Berkeley led to a transformative realization about how one person could do so much.
“I don’t know of anyone else who constantly has the kind of really great ideas and really fantastic research she has in so many different areas,” he said. “I don’t think she sleeps — that’s my theory.”
Dionne’s path to nanophotonics was serendipitous, if random. As an undergrad at Washington University in St. Louis, she majored in physics and in systems and electrical engineering. But she sampled widely and ultimately fell in love with the life of a scientist while doing summer oceanography research back in Rhode Island.
As graduation approached, she boiled her grad school choices down to two options — pursuing her new passion at the Scripps Institution of Oceanography in San Diego or continuing with her long interest in applied physics at Caltech. The decision was settled while she was touring Caltech’s Pasadena campus.
Another student on the tour began asking questions about the school’s nanofabrication facilities, an area Dionne knew next to nothing about. But the answers, however cryptic, fascinated her. She adopted an on-the-fly tactic of asking each new professor she met about a single nano-fab facility she had just learned about from the previous professor, cultivating the impression, she hoped, of knowing far more than she did.
Evidently it worked. Before she arrived as a student, she had an offer to do summer research with Atwater, a heavyweight in nanophotonics and now the editor of ACS Photonics, one of the field’s main journals.
Three years later, Dionne made it clear that his faith was well-placed. Working in Atwater’s lab, Dionne led the first experiment to show visible light bending backward in contradiction of hundreds of years of scientific understanding and millennia of observations.
The bending of light is a concept many of us learn about in high school, often with a picture of a half-submerged pencil that seems to break under the water’s surface. The illusion is created by the bending, or refracting, of light as it changes speed while traveling through different materials — in this case, water and air. The same basic phenomenon explains why rainbows form, diamonds sparkle and eye-glasses correct.
In nature, light bends only within a predictable cone of angles, as described by a scientific law dating to the 900s. But by the late ’60s, scientists began to theorize that exotic materials with unseen properties could bend light in radical new angles, a phenomenon called “negative refraction.”
After months of calculations, Dionne, working with Atwater and researcher Henri Lezec, created an experiment that essentially squeezed light along the silver-coated surface of a silicon-nitride wire. When the light hit a prism, the result was a blue-green glow where nature would never have put it, Dionne says, recalling the moment deep into the night when she first saw the results in her microscope. “That was definitely an amazing aha moment,” she says.
The discovery was more than just the miniature version of a funhouse mirror. It was a significant step in science’s fledgling mastery of light. Negative refracted light has different dynamics than “normal” light, offering hope for a way around the diffraction limit and a path to the more powerful optical microscopes Dionne dreams of.
“She just sort of assumes something is possible and then sets about
figuring out how to do it — the more challenging the better.”
And such manipulation of light dangled the promise of rendering objects invisible by steering photons around them, the way water passes around a rock in a stream — the reason Oprah came calling.
Dionne quickly followed with another breakthrough the same year, demonstrating the possibility of computer chips operating at the speed of light. Her work showed the elements of a photonic modulator, needed to make processors reliant on photons instead of electrons, which are sloth-like in comparison. Six years later, optical computing is still a distant goal, but her design continues to wow: “[T]his work for its completeness and originality is one of the cornerstones in nanophotonics,” an article in the January Journal of the Optical Society of America B stated.
Her success has the normal roots in hard work and dedication. Dionne herself cites focus rather than intelligence as a contributing factor in her rise. But those traits are a dime a dozen in the upper echelons of any field. What Dionne seems to display 16 years after leaving Bay View is an empowering naiveté about her own limits. The Brooklyn Bridge may not be in her sights, but other unlikely conquests are.
“I think she never even asks whether something is possible,” says Jennifer Roizen, an assistant professor of chemistry at Duke, who became friends with Dionne when both were at Caltech. “She just sort of assumes something is possible and then sets about figuring out how to do it — the more challenging the better. She is fearless.”
Dionne was apparently always hard-wired to wonder. Her mom, who died in 2012, often recalled how, as a toddler, Dionne was a font of questions and estimations about how long it would take to travel to Mars.
Dionne likens herself to the girl in comedian Louis CK’s bit about kids, responding to every explanation with another “why,” a process repeated ad absurdum and usually ending, in Dionne’s case, with her yet again being referred to the encyclopedia. “I wouldn’t stop,” she says.
By the time she was in high school, her facility with science, especially physics, was obvious. “There were times when the teacher was having difficulty explaining something and the class was getting more and more confused, and she just would raise her hand and say this, this and this,” her friend Nicole Bosse says. Bosse was no slouch herself, going on to earn a doctor of pharmacy degree, but she says Dionne just got the concepts on a deeper level.
Science, though, was far from her only passion. There was figure skating, gymnastics, yearbook, painting, philosophy and school in general. Dionne gave everything 200 percent, Bosse says.
Paying for such opportunities wasn’t easy for her parents, who sacrificed to provide for their only child. When Dionne was young, her dad, a construction supervisor, worked days and her mother, a registered nurse, nights, to avoid outside day care. Later, her mom drove two hours a day taking her to and from school and extracurricular activities.
Dionne rewarded their efforts by in-haling everything with gusto. Family lore could only explain it as an inheritance from her maternal grandmother, a dynamo who worked three jobs until late in life — at a jewelry-case factory, Dunkin’ Donuts and a record company — and then
went off to volunteer at a senior home, where she was older than most people she helped.
If something had to give, it might have been Dionne’s attention to pop culture. Her husband, Nhat Vu, who lived on the same floor freshman year, jokes that she was like a character from Blast from the Past, a comedy about a family reemerging into modern life after decades in a bomb shelter.
Today, her grandmother’s legacy remains in Dionne’s stores of energy, still apparent despite her widening professional responsibilities and the recent birth of her son, Marcus. (Dionne is the rare woman who, after going into labor, started to make brownies for the nurses, Roizen says.) She still runs 10 miles a week and aims to bike 60, preferably up Old La Honda Road, near campus.
In her lab, Dionne is a constant source of high-fives, over email if not in person, says Diane Wu, a fifth-year PhD student who works with the Dionne Group, a multidisciplinary team of 17 physicists, chemists and engineers. She is someone who frames work in the lab as an adventure, not a slog, and goes out of her way to spend at least one day a month in the lab. She remembers everything and wants her students to flourish, guiding them in how better to present their work.
“She is just so amazed by science and continues to be amazed that this is her job to do it,” Wu says. “She just really found what fit her.”
Sometimes, it pays to believe. •