Two Americans, German Win Nobel Prize in Physics for Laser Research

October 5, 2005

THE NATION
Two Americans, German Win Nobel Prize in Physics for Laser Research
# They are honored for work applying quantum theory to light and improving atomic study.

By Thomas H. Maugh II, Times Staff Writer

Two Americans and a German were awarded the 2005 Nobel Prize in physics on Tuesday for theoretical research explaining how lasers work and for practical developments using lasers to explore the fine structures of atoms.

Roy J. Glauber of Harvard University will receive half the $1.3-million prize for applying quantum theory to the light emitted by lasers, a feat that reconciled the dual nature of light, which behaves like both a particle and a wave.

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"You don't need Glauber's theory to invent the laser, but you do need it to understand its properties," said physicist Daniel Kleppner of the Massachusetts Institute of Technology.

John L. Hall of the JILA institute at the University of Colorado at Boulder and Theodore W. Hansch of Ludwig-Maximilians University in Munich will share the other half equally for their development of techniques to precisely control the frequency of lasers, thereby allowing measurement of physical properties not only of atoms, but of space and time, with unprecedented accuracy.

Such precision should enhance the accuracy of clocks and the global positioning system, improve the navigation of long spaceflights and help in the pointing of space telescopes, among other things, according to the Royal Swedish Academy of Sciences, which selected the winners.

Glauber, 80, said at a news conference that he was awakened early Tuesday by a phone call from someone with a Swedish accent.

"I could scarcely believe him," he said. He then heard the voices of "two other Swedish scientists I'm very well acquainted with, which perhaps at least raised the possibility that it was a joke."

But, he concluded, "there is something persuasive about that hour of the morning."

Asked by reporters what he was going to do with his share of the prize, he smiled and said: "Nobody mentioned money."

Hansch, 63, received the call from the academy in his office just before noon Tuesday as he was hurrying to catch a plane to San Francisco for a Friday seminar honoring laser inventor Charles Townes.

"My office manager told me she had to put through this call — a call from Stockholm," he said. "Right after taking the call, I hugged [her]."

He said it is still too early to know what benefits the laser developments will bring. "This is yet a young technology," he said. "It's hard to tell about how far a newborn baby might affect the world."

Hansch worked at Stanford University for 16 years before returning to Germany in 1986. He met Hall at Stanford when the Colorado scientist was taking a semester's sabbatical there.

"It's completely humbling to have the lightning strike," Hall, 71, said at a news conference at JILA, formerly the Joint Institute for Laboratory Astrophysics, run by the University of Colorado and the National Institute of Standards and Technology.

Two of his colleagues there, Eric A. Cornell and Carl E. Wieman, won the physics Nobel in 2001 for their creation of a Bose-Einstein condensate, an unusual state of supercooled matter.

Before Glauber published his seminal paper in 1963, researchers used classical optics theory from the 19th century to explain the behavior of light. Many researchers believed that quantum theory, which had proved successful in describing the behavior of matter, could not be applied to light.

But the development of the laser showed that the 19th century theory was fraying around the edges and could not be used to make accurate predictions for new applications.

"It occurred to me … that one had better develop the quantum theory to the fullest extent possible," Glauber said Tuesday.

His work "laid the foundations for future developments" in optics, the Nobel citation said.

The development of lasers operating at single frequencies made advances in the study of atoms and molecules possible. But those studies were limited, Hall said, by the inability to lock a laser onto a specific frequency.

His and Hansch's achievement, he said, was "learning how to stabilize a laser so its frequency doesn't change."

In addition to improved spectroscopy and analysis of chemicals, the development "has for the first time given us a practical way to measure the frequency of light," MIT's Kleppner said.

That, in turn, makes it possible to use newly developed atomic clocks that are accurate to 15 digits, compared with previous clocks accurate to 10 digits.

"Everyone is confident that there will be interesting and new applications" based on the more accurate clocks, he added.

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Times staff writers Petra Falkenberg and Christian Retzlaff in Berlin contributed to this report

http://www.latimes.com/news/science/la-sci-nobel5oct05,1,1484423.story?coll=la-news-science