It should come as no surprise to anyone that Henry C. Kapteyn, along with his wife and long-time research partner Margaret M. Murnane, received one of the American Physical Society's most prestigious honors in 2010: the Arthur L. Shawlow Prize in Laser Science. The Professor of Physics at the University of Colorado and Fellow of the Joint Institute for Laboratory Astrophysics (JILA) in Boulder, CO, received the honor in recognition"for pioneering work in the area of the ultra-fast laser science, including development of ultra-fast optical and coherent soft x-ray sources".
"We feel tremendously honored to be associated with one of the true greats in the area of laser science, and with our distinguished colleagues who have been honored in past years," says Kapteyn. "Being awarded the Schawlow prize is one of the true highlights of our career,"
Kapteyn has been pursuing this area of laser science with an especially rigorous passion for over 20 years. In the 1990's, he and Murnane developed new ultrashort pulse laser technology that lifted the veil on our comprehension of physics at the attosecond (one quintillionth of a second) regime, where electron motion can be spotted and tracked. Making use of this technology, he is also known for pioneering laser techniques that make coherent X-rays, which have a myriad of possible applications in science and for uses such as ultrahigh resolution medical imaging.
One such technique that Kapteyn has employed is called high harmonic generation (HHG). It is essentially a coherent version of Roentgen's 1895 x-ray tube, where coherent laser light is used to drive the high-energy electron collisions that generate the X-rays. Applications of HHG include probing materials dynamics, crafting holographic images, and analyzing molecular structure.
Kapteyn quips that, although he's had a few "a ha" moments in science, they've generally been outnumbered by the "uh oh" instances. As a physicist, he is always looking around for interesting twists on sexy problems, and as a professor, interesting methods in which to get his students attracted to analyzing those twists.
When the team hunkers down in the lab for a few months and finally emerges victorious, after the experiments produce something novel and previously unknown, it is clear that a quintessential moment of scientific discovery has transgressed. "That's when it gets pretty exciting," he says. "There are days when you come home and are just so excited about how things are going." Kapteyn's current goal is to create a light source for three-dimensional imaging of a single cell or nanostructures.
One of the areas of laser science that especially enchants the physicist, whose PhD is from UC Berkeley, is its use to address the more "general applications in society." Solving the world's energy problems fits this bill. A table-top femtosecond laser, in which pulses occur at 10 to the minus 15th of a second, has the ability to produce one terawatt of energy, which is "more power than in the entire grid," he says.
But if producing such significant quantities of power in a single light pulse is not enough, how about treating vision problems? Laser-assisted In Situ Keratomileusis, or LASIK, is a surgical procedure that is used to correct various eye ailments, such as myopia and astigmatism. "It's much safer than the scalpel," explains Kapteyn, although a vivid description of the surgery may leave something to be desired: in LASIK, "you're actually vaporizing the eye...[causing] a micro-explosion." But the benefits are tremendous because the laser is so precise, he says.
As for the laser's development over the last two and a half scores of years, "I'm not surprised by [its] progress," says the adroit analyst matter-of-factly. "Once you have laser light, it's energy in its purest form and you can control [its every] characteristic...You can sculpt the light form, even on a cycle-by-cycle basis." The technological advances that have been made possible by the laser will continue to expand our day-to-day abilities and mastery of science, he explains. "Light is very fundamental of our understanding of the natural world."