Robert D. Maurer Lecture 1998
Nobel Prize-Winning Physicist Lectures on Lasers

Lasers have come a long way since the first ruby crystal in the 1960's, Nobel prize-winning physicist Nicolaas Bloembergen told a University of Arkansas audience Thursday night, translating into a $20 billion market today. "In the 1960's, it was considered a solution looking for a problem," Bloembergen said of the first laser development. "Now, it's different. Now there are many problems solved by lasers."

Bloembergen, professor emeritus at Harvard, pioneered work on nuclear magnetic resonance with Edward Purcell and Robert Pound, as well as development of energy transfer schemes. He was awarded the Nobel Prize for physics in 1981 for his work on nonlinear spectroscopy and optics. Bloembergen spoke to a full house in Giffels Auditorium in Old Main. His presentation, "Lasers: Physics Impacting Your Life" was part of the Robert D. Maurer Lecture Series, named after the physics department alumnus and inventor of the first telecommunications-grade optical fiber. The lecture was sponsored by the physics department.

The word "laser," Bloembergen explained, is an acronym for "light amplification by stimulated emission of radiation." Because of the nature of the light amplification process, he said, light rays go in the same direction at the same frequency, and a coherent phenomenon occurs. Lasers have some common characteristics, including a high chromaticity (of color and wavelength), directionality (relating to direction in space), and high intensity and power. With the directional quality of lasers, he noted, distances such as from the Earth to the moon can be measured to within one inch of accuracy. On a large scale, they can be used to see changes in distance from one point on the Earth to another, detecting possible shifts in tectonic plates. On a smaller scale, they can be used to align underground or underwater pipelines and tunnels, such as the tunnel under San Francisco Bay.

The directionality of lasers also enables laser communication. Lasers can focus onto an area of an optical fiber of one micrometer squared, or as Bloembergen explained, "one thousandth of a cross-section of a human hair, if you can imagine that," making them practical in large cities where there is no more room to lay copper cables for communication. "One optical fiber can carry 400,000 simultaneous telephone conversations," he noted, "so it can do more than 100,000 copper wires."

There are now more than a dozen optical fibers from the East coast to Europe, with a similar number extending across the Pacific. Lasers are also important in the development of optical discs for mass storage requirements, Bloembergen said, and in the automotive industry for heat treatment of metal cylinders in combustion engines, as well as laser beam welding systems.

Lasers can also cut materials like paper, textiles, and diamonds, and one of their most interesting uses, he said, is in medicine. They have many uses in surgery, such as to repair detached retinas or remove port wine stains, and their use is cleaner, with less blood loss, and more precision than standard surgical instruments.

Bloembergen sees laser use increasing in scientific applications, and said there is an "enormous push" now for high-powered, semiconductor lasers. Bloembergen has authored two monographs, "Nuclear Magnetic Relaxation" and "Nonlinear Optics," and published more than 300 papers in scientific journals. He was president of the American Physical Society, and has won a number of national and international awards, including the Lorentz Medal of the Royal Dutch Academy of Sciences and the U.S. National Medal of Science. A reception followed his presentation.

By Dana Gieringer, The Morning News of Northwest Arkansas, Reprinted with permission