Issue of
May 31, 2000

Memorial Resolution: Arthur Schawlow

ARTHUR L. SCHAWLOW

(1921-1999)

Arthur Leonard Schawlow was born in Mount Vernon, New York on May 5, 1921. The family moved to Canada a few years later. As a young boy, Art showed both a scientific aptitude and a love of tinkering with gadgets which stayed with him throughout his life. He graduated from high school at the age of 16 and originally intended to study radio engineering at the University of Toronto. Unable to afford the tuition, he was guided into his future career by a scholarship to study mathematics and physics. He continued on at Toronto and received a Master's degree in 1942 and a Ph.D. in 1949. During those years, his basement spectroscopy laboratory often reverberated with the sounds of Benny Goodman, "Jelly Roll" Morton, as well his own passable clarinet playing of Dixieland jazz.

In 1949, Charles Townes offered him a post-doc position at Columbia University to work on microwave spectroscopy. He soon began to write with Townes the seminal book Microwave Spectroscopy, published in 1955. He met and married Townes' youngest sister, Aurelia, a talented vocalist. In 1951, Schawlow joined Bell Telephone Laboratories with the intent to work with John Bardeen on superconductivity. By the time Art arrived, Bardeen had departed, but Art decided to work on superconductivity nevertheless and did sound but not earthshaking work.

Townes was a consultant at Bell Laboratories. In 1957, he discussed with his brother-in-law and former post-doc the possibility of extending the maser concept to the optical region. Art showed immediate interest since he had also been thinking along these lines. Their collaboration led to a famous paper "Infrared and Optical Masers," published in 1958. A key idea introduced by Art was the suggestion that the so-called Fabry-Perot parallel two-mirror arrangement could be used to create an optical cavity needed to sustain lasing action. The basic patent for the laser (an acronym for Light Amplification by Stimulated Emission of Radiation) was awarded to Schawlow and Townes in 1960. During the same year, the first experimental laser was demonstrated by Ted Maiman at Hughes Aircraft.

In 1961, Art left Bell Laboratories to join the faculty at Stanford University where he remained until he retired in 1996. He embarked on a remarkable career developing laser spectroscopy. With Ted Hänsch, a research associate from Germany and then a faculty member at Stanford from 1975 to 1986, he co-invented an extremely precise form of optical spectroscopy, called saturation spectroscopy. Starting with iodine molecules and sodium atoms, they moved on to the hydrogen atom to make the most precise measurement of the magnetic moment of the electron using Doppler-free two-photon spectroscopy.

In 1975, Schawlow and Hänsch proposed that laser light could be used to cool atoms in the gas phase to extremely low temperatures. Their idea, demonstrated ten years later at Bell Laboratories, became an important tool in atomic physics. In 1981, Art was awarded the Nobel Prize for "his contributions to the development of laser spectroscopy."

Other contributions by Art to the advancement of science were less tangible, but perhaps equally important. He brought the joy and wonder of science not only to his scientific colleagues, but also to the general public. In a demanding, and often exhausting, lecture schedule that spanned several decades, he communicated his playful approach to science. He spiked his talks with jokes, at which he was the first to laugh. For Art, physics was fun and he made it more fun for the rest of us.

A much used demonstration, breaking a blue "Mickey Mouse" balloon inside a clear outer balloon with a portable laser (in the shape of a ray gun, of course!), showed that a light beam can affect a region inside the outer balloon without damaging it. This idea re-surfaced when lasers were used in the repair of detached retinas. More recently, a similar concept appeared in "optical tweezers," an optical trap fashioned out of a single focused laser beam. This trap, holding atoms and sub-micron sized particles, has allowed reaching inside a living cell to manipulate organelles and even chromosomes, without damaging the cell or nucleus membrane.

One of Schawlow's amusing inventions was the "laser eraser" to correct typewriter typos. Although overtaken by word processing, another one had important consequences. Guided by his postulate that "anything will lase if you hit it hard enough," he and Ted Hänsch strove to create the first "edible laser" made from Jell-O dessert. Working with two flavors per day, they marched through all 12 flavors of Knox brand Jell-O. Unfortunately, none of the gelatin desserts showed lasing action, and Art retreated back to his office where he ate each of the failures! Eventually, he and Ted spiked the Jell-O with sodium fluorescein, a known laser dye, and immediately saw lasing action. The news of the "almost edible" laser spread rapidly and was published in 1971. It stimulated the production, at Bell Laboratories, of a two-laser interference pattern in a photographic gelatin film, which allowed the development of a new type of laser (distributed feedback) widely used in long distance optical fiber communication.

Art's many contributions not only had a profound impact in physics, but also in chemistry, biology, medicine, and continue to be a major driving force in many aspects of modern technology. The careers of only few scientist/inventors have had such wide ranging impact. In recognition of his work, Art received numerous awards, honorary degrees, and election to honorary societies. Two prizes were named after him: the Laser Institute of America established the Arthur L. Schawlow Medal for Laser Applications, and the American Physical Society the Arthur L. Schawlow Prize for Laser Science. Although he did not seek office (and was a reluctant Physics Department chairman from 1966 -1970), he served as president of the American Physical Society and as president of the Optical Society of America.

In addition to being an eminent scientist, Art was an entertaining lecturer and a beloved mentor. He attracted a large number of students and post-docs who affectionately called him "the Boss." He showered fatherly advice and maxims on them to the point where "the sayings of Art Schawlow" became known beyond Stanford's Physics Department. To young scientists intimidated by information overload, he would say, "to do successful research, you don't need to know everything, you just need to know one thing that isn't known." Art felt that one of the hallmarks of a successful scientist is a driving need "to find the answer" and towards this goal, "anything worth doing is worth doing twice, the first time quick and dirty, and the second time the best way you can." Having been infected with his charm and vision, many of his flock have gone on to do great science.

While at Stanford, Art's wit and humor became renowned. Once he gave a physics colloquium at Stanford entitled "Is Spectroscopy Dead?" He began the talk by defining, at great length, what he meant by "spectroscopy." Following this long introduction, Felix Bloch asked, "Now define 'Dead.' " After a thoughtful pause, Art answered, "Dead is when the chemists take over the subject." Art could say this and make even the chemists laugh. In addition to his dedication to physics, Art Schawlow was a devoted husband and father of three children. His son Artie has autism and he and Aurelia devoted much time and energy to caring for their son. Their efforts included organizing a nonprofit corporation to provide a group home for autistic persons and the championing of facilitated communication by computer keyboard as a means of communicating with autistic individuals.

While traveling to see her son, Aurelia died in 1991 in an accident. This, and a later discovery of a virulent form of leukemia, produced difficult years for Art, during which his family, and his love for science and for jazz provided much support. His encouragement of younger persons who visited him or cared for him continued until the end. He died on April 28, 1999.

Arthur Schawlow was not just admired, he was cherished by those who knew him. He was a great scientist of remarkable modesty, a supportive teacher, a gentle leader, and above all, a caring human being.*

Committee:

Blas Cabrera

Steven Chu

Walter Meyerhof

*Most of the material for this Memorial Resolution was taken from an obituary by Steven Chu in Physics World, August 1999 (The Institute of Physics Publishing, Bristol, United Kingdom, by permission).