The Race to Build a Laser
The race was on! When Schawlow and Townes published their ideas in 1958, physicists everywhere realized that an "optical maser" could be built. Teams at half a dozen laboratories set out, each hoping to be the first to succeed.
Columbia University. Schawlow left it to Townes to make the first attempt. Townes decided to start with potassium gas, since its properties were well understood. But one of these properties is that it is corrosive. The gas attacked the seals on Townes’s glass tubes and darkened the glass.
TRG Corporation. When Schawlow and Townes published their work, Gould told his employers that he was working along the same lines. They got funding for a project from the US Department of Defense. The project was classified "secret", and Gould was barred from working on it because he had briefly participated in a Marxist study group during the war.
Westinghouse Research Laboratories. Masers were being made not just from gas but from crystals — synthetic ruby, for one. Perhaps a crystal might be stimulated to emit visible light. Irwin Wieder and collaborators tried pumping energy into a ruby, using a tungsten lamp. The system was hopelessly inefficient — they couldn’t get nearly enough energy into the atoms to make a laser.
IBM. At IBM’s Thomas J. Watson Research Center, Peter Sorokin realized that you didn’t need mirrors if you used a crystal with the right properties. He had a calcium fluoride crystal polished to have square sides. A ray striking an edge at a 45-degree angle would be reflected towards the next edge and continue to go round and round the inside. A trace of uranium atoms sprinkled through the crystal could act like a gas in a cavity. But they couldn't get laser action, that is, amplification of light.
Bell Labs. Bell Labs had a good supply of rubies for maser research, and Schawlow decided to try that route. Meanwhile Ali Javan, a former student of Townes, tried another route. Like Townes, Javan prefered the simple medium of a gas, and he settled on a combination of helium and neon in a long glass tube. An electric discharge through the gas would energize the helium, and collisions would transfer that energy to the neon. They too couldn't get laser action.
Hughes Laboratories. Theodore Maiman made calculations and measurements that convinced him Wieder was wrong in saying it was impossible to pump much energy into a ruby. Even so, you would need an extraordinarily bright energy source. One day Maiman realized the source did not have to shine continuously, which was what Schawlow and others were trying. A flash lamp would do. Scouring manufacturers’ catalogs, he found a very bright lamp with a helical shape. Just right, he thought, for fitting a ruby inside. He assembled the components with the aid of an assistant, Irnee d’Haenens, and on May 16, 1960 they observed pulses of red light. It was the world’s first laser.
More reading: How the ruby laser works from LaserFest (opens in new window)
Other teams moved quickly when they heard of Maiman's work. Within a couple of weeks of the press conference that announced the discovery in July, groups at Bell Labs and TRG had bought flashlamps like the one shown in Maiman's publicity photo, reproduced his device and studied it in detail.... Schawlow, who had joined the Bell group, with his technician George Devlin made a laser out of a different type of ruby crystal.... Wieder with Lynn Sarles independently got the same result.... When Sorokin heard of Maiman’s achievement, he realized that he had been too pessimistic. He and Mirek Stevenson had their calcium fluoride crystals recut into cylinders silvered at their ends, and got laser action from them in Novermber. The input power required was less than 1% of that needed for the ruby laser.... Back at Bell Labs, Ali Javan with Donald Herriott and William Bennett continued on their original path, and in December produced a continuous beam of infrared rays — the first gas laser. Altogether, by the end of 1960 three quite different types of laser had been demonstrated.