& Attoseconds: A Moment With the Scientist Behind the Shortest Laser Pulse

Zenghu Chang, in the Florida Atto Science and Technology Lab at UCF. He is wearing goggles to protect his eyes from the laser light. Photo by Susan Frith.

Briefly returning to the A’s at the Curiosity Dispensary … Before I enter Zenghu Chang’s lab at the University of Central Florida, he hands me a pair of blue booties and tells me to put on some safety goggles. The booties help keep out the dust. The goggles will protect my eyes from intense laser light. Inside the Florida Atto Science and Technology Lab, a research team led by Chang has used a new optical technique to generate the shortest laser pulse on record—just 67 attoseconds (or 67 quintillionths of a second) in duration. Their results appear in the journal Optics Letters. Chang’s accomplishment brings scientists a step closer to the goal of being able to observe chemical reactions as they unfold.

When I think of incredibly short bursts of time, I think of Olympic sprinters crossing the finish line. I think of speeding bullets. (I think of how long I am actually sitting down at the dinner table before my kids start haggling over what they have to eat to get dessert.)

Dr. Chang, a professor of optics and physics, works in a whole different world—the world of the attosecond. In the time it takes you to blink your eye, he explains, 1015 attoseconds have passed. Comparing an attosecond to a second is like comparing one second to twice (actually 2.3 times) the age of the universe. Continue reading