Prof. Charles Townes
Engineer, Scientist, and Co-Inventor of the Laser.
Nobel Peace Prize Winner
LASER is an acronym for "light amplification by stimulated emission of radiation." A laser produces a thin beam of light that is monochromatic and coherent, meaning that the beam is one color and each wave of lighttravels in step. The laser process begins when energy enters and begins to strike the atoms in a system. The stimulated atoms give off energy in the form of light. This emitted light reflects back and forth between the ends of a cylinder, one end being a fully reflecting mirror and one end being a partially reflecting mirror. The light continues to excite more and more atoms, and finally the atoms contain enough energy to burst through the partially reflecting mirror in a beam of light. This beam of light has a variety of applications. For instance, it is able, in some cases, to drill tiny holes in diamonds within minutes (conventional methods take days to produce the same holes).
The laser's history can be divided into the pre-maser period, the maser period and the laser period. The basics involving the pre-maser period begin at the atomic level. In 1916, Albert Einstein discovered a process called stimulated emission involving the interaction between electromagnetic radiation and atomic energy states [Lengyel, 1966]. Charles Townes produced the first maser and asked Albert Schawlow to help in his progress towards the laser in October of 1957. Gordon Gould was also intrigued by the idea of the laser [Bromberg, 1991]. At Columbia University, and later at Technical Research Group (TRG), Gould had the chance to develop and extend his ideas about the laser and its capabilities. In November of 1957, he had his now famous notebooknotarized containing his initial ideas for the laser.
Townes and Schawlow had astounding careers in physics, both winning Nobel prizes. Two documents give a solid representation of their research. The first was a paper titled "Infrared and Optical Masers," published by the Physical Review in 1958 [Schawlow and Townes, 1958], and the latter was the patent granted to them in 1960 titled "Maser and Maser Communications System" [Schawlow and Townes, 1960]. Schawlow and Townes challenged themselves to reduce the laser to practice and knew of the difficulties of such a task.
Schawlow and Townes presented many ideas towards laser technology. Their research allowed for a well deserved patent in 1960. Their patent claims surround a communications system involved in operating masers at optical frequencies [Schawlow and Townes, 1960]. When used for communication purposes, the laser has to have a relatively low energy output. This useconstrained the patent granted to Schawlow and Townes. Even though the laser is often used in communication, other applications for which the laser is used require higher outputs. One example is the laser cutting of materials. Schawlow and Townes did not account for this kind of use in their patent, and doubts arose as to the patent's validity. The U.S. Patent Office ruled in 1973 that the patent did not supply enough information to make certain key parts ["A Laser," 1977]. Furthermore, the patent was too general and provided a disparity in interpretations, leading to many legal disputes.
Similar to Schawlow and Townes's deduction, Gould figured that sodium vapor would provide an excellent excitable medium to produce stimulated emission of light [Lengyel, 1966]. However, Gould's work addressed the higher output capability of the laser and its possible applications at these levels.
Fight of Gordon Gould
Arthur Schawlow and Charles Townes received the first patent on the laser in 1960. This awarding of the patent came after Gould had submitted his application and been denied. Gould was not satisfied with this ruling, however, and fought for his patent rights. His notarized notebook came in handy at this time. Gould desperately fought the decision with appeals and with court cases both in America and internationally ["A Laser," 1977]. A major blow came in 1966 when the US Court of Customs & Patent Appeals denied his request for a patent. Gould altogether spent nearly $100,000 of his own money, and TRG supported him with $250,000. Still, Gould fought and won minor battles on the way in Canada and Britain.
In 1973, the same U.S. Court of Customs & Patent Appeals made a decision that gave Gould a window of opportunity to renew his quest for a patent [Hecht, 1994]. The court ruled that much of the Schawlow-Townes patent did not accurately describe part of the process for creating a laser. This ruling made much of the Schawlow-Townes patent obsolete ["A Laser," 1977]. Gould saw his opportunity and brought on Refac Technology Development Corporation to help in his fight. Little attention was given by the laser industry to GouldÕs new quest for a patent.
This lack of attention changed, however, when the U.S. Patent Office granted Gould the patent rights to the laser. Refac soon began to collect fees, and GouldÕs work had finally paid off. He continued to apply for more patents, and Gould received his fourth and final patent on lasers in 1988.
GouldÕs quest for the patent on the laser was long and difficult. In reality, Schawlow, Townes and Gould all made contributions toward the development of the laser. It is unfortunate that sometimes credit has to be placed upon one individual. Each man gave his talents to the laser industry, and without any of them, the laser probably would not have affected the world the way that it continues to do today.
Author Bio: Todd Fronek is a senior in Industrial Engineering at the University of Wisconsin. After completing his degrees, he intends to go to law school.
Bromberg, Joan L., "The Birth of the Laser," Physics Today (October 1988), pp. 26-33.
Bromberg, Joan L., The Laser in America (Cambridge, Massachusetts: The MIT Press, 1991).
"A Laser Patent That Upsets the Industry," Business Week, no.2506 (24 October 1977), pp. 121-130.
Hecht, Jeff, "Winning the Laser Patent War," Laser Focus World (December 1994), pp. 49-51.
Lengyel, Bela A., "Evolution of Masers and Lasers," American Journal of Physics, vol. 34, no. 10 (October 1966), pp. 903-913.
Schawlow, Arthur L., and Charles H. Townes, U.S. Patent No. 2,929,222 (22 March 1960).
Schawlow, Arthur L., and Charles H. Townes, "Infrared and Optical Masers," Physical Review, vol. 112, no. 6 (15 December 1958), pp. 1940-1949.