Charles Hard Townes

American physicist

• Born: July 28, 1915
• Birthplace: Greenville, South Carolina
• Died: January 27, 2015
• Place of death: Oakland, California

A prolific scientist and influential educator, Townes is credited with the fundamental research leading to the development of the laser, one of the most significant technological phenomena of the twentieth century.

Early Life

The fourth of six children born to attorney Henry Keith Townes and Ellen Hard Townes, Charles Hard Townes (townz) spent his formative years on a small farm on the outskirts of Greenville, South Carolina, where he developed a fascination for both natural and physical sciences. At an early age, Townes demonstrated prodigious academic ability, graduating from high school at age sixteen and enrolling at Furman University in Greenville. He earned bachelor’s degrees with honors in both physics and modern languages at age nineteen, while competing for the university swim team, playing for the marching band, and serving as curator of the school’s natural history museum.

As a young man, Townes had shared an interest in biology with his brother Henry, who would later become a professor of entomology. Under the direction of professor Hiden Cox, Townes became enamored with what he would later call the “beautifully logical structure” of physics. Following his graduation from Furman in 1935, Townes attended Duke University, completing the requirements for a master’s degree in physics in one year. By 1936, he had entered a doctoral program at the California Institute of Technology (Caltech). Three years later, Townes, still in his mid-twenties, received a PhD in physics from Caltech and began work at the prestigious Bell Laboratories as a research scientist.

Life’s Work

At Bell Labs, Townes conducted research that led to the development of numerous advances in electronics and communications, including the transistor, which would replace vacuum tubes in electronic devices. In 1941, with US involvement in World War II imminent, Townes focused his research upon the development of radar devices, which revolutionized warfare by utilizing electromagnetic waves to detect the presence and movement of aircraft, ships, troops, and equipment.

Townes’s wartime work with radar intensified his interest in the properties of microwaves, high-frequency electromagnetic signals that in earlier research had shown promise as a medium for wireless communication and energy transfer. In the late 1940s, while researching the effects of microwave radiation upon molecular structures, Townes discovered that weak microwave beams fired through a gaseous medium such as ammonia were strengthened by molecular changes in the gas. This discovery led Townes to explore the potential practical uses of microwaves amplified through this process, known as stimulated emission.

Townes continued his research in microwaves at Columbia University, where he was named associate professor of physics in 1948 and a full professor in 1950. In 1951, while sitting on a park bench, Townes conceived the idea of a device capable of amplifying and concentrating microwaves in a powerful beam to produce intense, localized heat or to conduct precise measurements. In 1953, Townes, with assistance from his graduate students at Columbia, constructed a working model of this device, which he called a maser (acronym for microwave amplification by the stimulated emission of radiation).

The maser, although a key step in the development of laser technology, produced a signal too weak to perform most of the functions for which the laser was eventually utilized. Its practical applications, although significant, were thus limited to tasks requiring low levels of energy emission, such as radiation detection and the operation of atomic clocks. However, Townes had also pondered the possibility of applying stimulated emission to a beam of optical light, which would produce an intense concentration of energy that he theorized would be powerful enough to cut metal or stone but sufficiently precise to perform highly delicate tasks such as surgery. In the mid-1950s, Townes, in collaboration with his brother-in-law, Arthur L. Schawlow (who had married Townes’s sister, Aurelia, in 1951), commenced efforts to develop a working model of an “optical maser.”

In 1957, Townes and Schawlow published a paper describing how stimulated emission could be used to create a highly concentrated and amplified beam of light, a significant step towards the invention of the laser. During this time Townes also engaged in several discussions with Columbia graduate student Gordon Gould on the potential of this technology. Gould subsequently focused his research upon producing a working model of such a device, which he dubbed a laser (acronym for light amplification by the stimulated emission of radiation). Two scientists from the Soviet Union, Nikolay Gennadiyevich Basov and Aleksandr Prokhorov, also had been working independently on developing similar devices.

During the late 1950s, a race ensued between several teams of researchers including Townes, Schawlow, Gould, and California-based physicist Theodore H. Maiman to produce a working model of the laser. Although Maiman would produce the first working laser in May 1960, Townes and Schawlow already had been awarded the original patent on the strength of their mid-1950s research into the optical maser. Gould subsequently challenged the patent, precipitating a three-decade legal battle that ended in 1987 when Gould was awarded patents for two versions of the laser. In 1964, Townes, Basov, and Prokhorov were awarded the Nobel Prize in Physics for their pioneering work in the development of the laser.

While others worked to perfect laser technology, Townes returned to teaching and research, serving as director of research for the Institute for Defense Analyses from 1959 to 1961 and as provost at the Massachusetts Institute of Technology from 1961 to 1967. Townes joined the faculty at the University of California, Berkeley, in 1967, where he conducted research in quantum electronics and astronomy. His work at Berkeley included the use of laser technology to analyze the chemical composition of interstellar space and the discovery and measurement of astronomical phenomena known as black holes.

During the latter decades of the twentieth century, Townes became one of the world’s most revered physicists, receiving numerous honorary degrees, fellowships, and lectureships, and serving on several governmental advisory committees and corporate boards. He was presented with the National Medal of Science in 1982. Despite officially retiring from teaching and research in 1986, Townes remained active into the twenty-first century, publishing a memoir of his scientific career and teaching and supervising graduate student research in astrophysics at Berkeley. He supported several activist efforts, campaigning with a group of Nobel laureates for a ban on nuclear tests in 1999 and opposing US involvement in Iraq in 2003.

Townes also received numerous honors in his home state of South Carolina. In 1980, he became the first living person inducted into the South Carolina Hall of Science and Technology, and in 1986 the science hall of the South Carolina State Museum was named for him. The early twenty-first century saw a resurgence of interest in Townes in his hometown of Greenville, which saw the construction of a science center named in his honor at Furman University and the dedication of a statue in downtown Greenville depicting Townes on a park bench at the moment that he conceived the idea for the laser.

A lifelong Christian, Townes also was known for his efforts to bridge the historical rift between religious faith and scientific inquiry that had intensified in the United States with the rise of religious fundamentalism during the twentieth century. In 2005 he received the Templeton Prize, awarded to scholars whose work has advanced knowledge of relationships between scientific and religious matters. He received numerous other awards including the 2012 Golden Goose Award, which is given for "seemingly obscure studies that have led to major breakthroughs and resulted in significant societal impact," according to the organization's website. 

After a period of declining health, Townes died in Oakland, California, on January 27, 2015. He was ninety-nine years old, and was survived by his wife, Frances; the couple had married in 1941 and had four daughters.

Significance

Spanning eight decades, Townes's career was marked by numerous contributions to modern science and technology, ranging from the abstract to the practical. His research and writings have influenced generations of scientists and laypersons, and his contributions to the development of various technological devices, from the transistor to radar, have exerted immeasurable impact upon modern life.

The pioneering role of Townes in the development of the laser is typically regarded as his most significant contribution to modern technology. Compact, powerful, and precise, the laser proved useful for performing a variety of functions, including wireless communication, measurement of distance and density, surgery, medical diagnosis, and chemical analysis. Perhaps the most common modern application of the laser is as a means of storing and scanning digital information in digital video disc (DVD) devices and in bar codes and other identification tags used in the retail and security industries.

Bibliography

Bertolotti, Mario. The History of the Laser. Bristol: Inst. of Physics, 2005. Print.

Chaio, Raymond Y., ed. Amazing Light: A Volume Dedicated to Charles Hard Townes on His Eightieth Birthday. New York: Springer, 1996. Print.

"Charles Hard Townes." Columbia Electronic Encyclopedia, 6th Edition (2013): 1. Academic Search Complete. Web. 18 Dec. 2013.

Hecht, Jeff. Beam: The Race to Make the Laser. New York: Oxford UP, 2005. Print.

Taylor, Nick. Laser: The Inventor, the Noble Laureate, and the Thirty-Year Patent War. New York: Citadel, 2003. Print.

Townes, Charles H. How the Laser Happened: Adventures of a Scientist. New York: Oxford UP, 2000. Print.

Townes, Charles H. Making Waves. New York: Springer, 1994. Print.

Waynant, Ronald W., ed. Lasers in Medicine. Boca Raton: CRC, 2002. Print.