That lasers were possible could be inferred as early as 1917, when Albert Einstein published his “On the Quantum Theory of Radiation” paper. But it was 43 years before a researcher, Theodore Maiman, built a laser that worked. That first laser, invented 50 years ago, has now been declared an IEEE Milestone in Electrical Engineering and Computing.
Einstein’s paper had shown that an atom excited to a high quantum energy level emits radiation of a specific wavelength when acted upon by radiation of that wavelength. But use of that stimulated emission phenomenon had to wait for technologies not developed until World War II and later. The existence of stimulated emission wasn’t demonstrated until 1947, and the first device to use it, the maser, short for “microwave amplification by stimulated emission of radiation,” wasn’t developed until 1953. The output of the first maser, developed by IEEE Life Fellow Charles H. Townes and graduate students James P. Gordon, an IEEE Life Fellow, and Herbert J. Zeiger, was noncontinuous. Russian physicists Nikolai Basov and Aleksandr Prokhorov developed a continuous-output maser that same year. For their work, Townes, Basov, and Prokhorov received the 1964 Nobel Prize in Physics.
THE SEARCH IS ON
The maser’s existence started a widespread search for ways to make an “optical maser”—dubbed a “laser,” for “light amplification by stimulated emission of radiation,” in a 1958 paper by Gordon Gould, a graduate student at Columbia University. The search only intensified after the publication of a paper on laser theory by Townes and Bell Laboratories’ Arthur L. Schawlow, an IEEE Life Fellow, and a 1959 conference on quantum electronics organized by Townes for the U.S. Office of Naval Research. One of the researchers galvanized by that conference was Theodore H. Maiman, a physicist at Hughes Aircraft Co.’s research laboratories in Malibu, Calif.
Maiman, who had been working at Hughes with masers built with synthetic rubies, used that material for his experimental laser despite other physicists’ views that ruby lasers wouldn’t work. The energy that excited the atoms in the laser’s synthetic ruby came from an off-the-shelf, helical, photographic flash lamp surrounded by a cylindrical reflector, with a rod of synthetic ruby placed at the center of the helix where it would receive energy from all sides. The device converted the flash lamp’s white light, containing randomly phased light of all colors, to monochromatic red light that was coherent. In other words, the red light’s waves all moved in phase with one another and in the same direction. Such a beam doesn’t spread much over distance and is made more intense by the absence of phase interferences between its waves.
The output from Maiman’s laser was pulsed rather than continuous—which limited its potential applications. The first continuous laser was developed the following year by Ali Javan and others at Bell Laboratories. However, the simple construction of Maiman’s laser showed that lasers could be practical to manufacture and apply.
But what could it be used for? For years, popular articles about the laser called it “a solution in search of a problem.” Some trumpeted it as a potential superweapon or death ray (laser research was heavily supported by the military). But problems the laser could solve turned up almost everywhere else. Its first practical application came in 1961 in the delicate field of eye surgery, eradicating a patient’s retinal tumor.
Building a research team, Rudi Kompfner, Bell Labs research director and 1973 IEEE Medal of Honor recipient, enticed one plasma physics researcher into optical communications by saying, “Think of all that bandwidth!”
The laser, and fiber optics, did revolutionize communications. But few could have predicted how ubiquitous lasers would become. In addition to medicine and communications, the laser is widely used in fields such as spectroscopy, for precise cutting of materials that include paper and sheet metal, nuclear fusion, security, the military, archeology, meteorology, and microscopy. Laser printers abound, supermarkets use lasers to scan bar codes, and lasers are in every home with a DVD or CD player.
Maiman, who died in 2007, garnered two Nobel Prize nominations and many other honors for his work. One of the many commemorations of Maiman’s laser on its 50th anniversary was the unveiling of the IEEE Milestone plaque at a ceremony on 23 November. The plaque—placed inside the building housing the former Hughes Research Laboratories in Malibu, now jointly owned by Boeing and General Motors—reads:
First Working Laser, 1960
On this site in May 1960 Theodore Maiman built and operated the first laser. A number of teams around the world were trying to construct this theoretically anticipated device from different materials. Maiman’s was based on a ruby rod optically pumped by a flash lamp. The laser was a transformative technology in the 20th century and continues to enjoy wide application in many fields of human endeavor.