Remembering Laser Theory Pioneer Charles Townes

His contributions earned him the Nobel Prize and the IEEE Medal of Honor

30 January 2015

Photo: University of Central Florida

*ThisDVD and Blu-ray players, surgical equipment, bar-code readers, and 3-D printers are just some of the technologies made possible by lasers. The laser and its predecessor, the maser, were codeveloped by IEEE Fellow Charles H. Townes, who died on 27 January at the age of 99.

The first maser—short for “microwave amplification by stimulated emission of radiation”—was developed in 1953 by Townes, IEEE Life Fellow James P. Gordon, and Herbert J. Zeiger, but the light was noncontinuous. The maser was the result of Townes’ efforts to obtain stronger radiation with shorter wavelengths using a source other than a vacuum tube.

The discovery of the maser inspired a search for ways to make an optical maser, or “laser.” A laser differs from other sources of light because it emits continuous, coherent light. This allows a laser to be focused to a tight spot and enables its beam to stay narrow over long distances. Townes worked for about nine years with his brother-in-law, Life Fellow Arthur Schawlow, a Bell Laboratories researcher, to complete the theory and design for the laser.

The device they helped develop could operate at wavelengths a thousand times shorter than masers. It also went on to change the sciences of optics and electronics. However, Townes and Schawlow never profited from the technology.

The first person to develop a working laser was Theodore Maiman. A researcher at Hughes Aircraft Co., in Glendale, Calif., Maiman built his laser in 1960 with synthetic red ruby. In 2010 this breakthrough was named an IEEE Milestone in Electrical Engineering and Computing.*

Russian physicists Nikolai Basov and Aleksandr Prokhorov also developed a continuous-output maser in 1953. For their work, Townes, Basov, and Prokhorov received the 1964 Nobel Prize in Physics. Townes was the recipient of the 1967 IEEE Medal of Honor, the organization’s highest award, for his “significant contributions in the field of quantum electronics which have led to the maser and the laser.” He also received the 1982 U.S. National Medal of Science.

According to a 2005 interview with NPR’s Morning Edition, Townes wanted to use laser light as a precision tool for his research on molecules. He spent a long time thinking about similar devices that didn’t quite pan out. Finally, the basic concept for a laser came to Townes in the spring of 1951, as he sat on a park bench in Washington, D.C.

EARLY START

According to the book Sparks of Genius: Portraits of Electrical Engineering Excellences [IEEE Press, 1994], Townes had an early fascination with gadgets and inventing. The book republished the Christmas list the 10-year-old Townes gave to his sister Mary: tin shears, a flat file, a pair of glass cutters, some iron and wood bits, penny nails, and rifle shot. (He didn’t mention what he intended to do with these items.)

According to his 1992 oral history on the IEEE Global History Network, Townes was 19 when he earned a bachelor’s degree in physics in 1935 from Furman University, in Greenville, S.C.—graduating summa cum laude, no less. He went on to earn a master’s in physics in 1936 from Duke University in Durham, N.C., and a Ph.D. in physics in 1939 from Caltech. That same year, Townes became a research physicist at Bell Labs in New York City, where he collaborated with a variety of research groups and received a number of patents. He left there in 1948 to join Columbia as an associate professor of physics, where he continued his research on the microwave spectroscope. Most of his years at the university were spent as a consultant to Bell Labs. He served as executive director of the school’s Radiation Laboratory from 1950 to 1952, and was chair of the physics department from 1952 to 1955. 

Townes took a leave of absence from 1959 to 1961 to serve as vice president and director of research at the Institute for Defense Analyses in Washington, D.C. The nonprofit advised the U.S. government and was operated by 11 universities.

In 1961, Townes was appointed provost and professor of physics at MIT and in 1966 was appointed Institute Professor. He resigned as provost that same year to return to more intensive research, particularly in the fields of quantum electronics and astronomy.

Townes left MIT in 1967 to join the University of California, Berkeley, as a professor of physics. There, Townes became an astronomer. In 1985, he helped discover the black hole that lives at the center of our Milky Way.

Until last year, Townes, a professor emeritus, visited the campus daily, working either in his office in the physics department or at the Space Sciences Laboratory.

“Charles Townes embodies the best of Berkeley; he’s a great teacher, great researcher and great public servant,” said UC Berkeley chancellor Nicholas Dirks at a campus-wide celebration of Townes’ 99th birthday last July. “As we celebrate this 99-year milestone and a career spanning nearly 80 years, we can only be impressed by the range of his intellectual curiosity, his persistence, and his pioneering spirit.”

SCIENCE AND FAITH

In addition to his other achievements, Townes received the US $1.5 million Templeton Prize for contributions to the understanding of religion. He saw his faith as intertwined with his science.

“Religion is an attempt to understand the purpose and meaning of our universe,”  he said in the 2005 NPR interview. “What is science? It’s an attempt to understand how our universe works. Well, if there’s a purpose and meaning, that must have something to do with how it works, so those two must be related.”

*This article has been revised. 

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