Coherent Light

Theodore Maiman did not believe it would work. In his laboratory at Hughes Research in Malibu, he had spent months trying to build something most physicists thought was impossible: a device that could amplify light into a coherent, focused beam. On May 16, 1960, it worked. A small synthetic ruby crystal, pumped with energy from a flashlamp, emitted a pulse of deep red light -- perfectly coherent, perfectly aligned. The first laser.

The concept had been proposed in the 1950s by Charles Townes and Arthur Schawlow, building on Albert Einstein's 1917 theory of stimulated emission. But theory and execution are different problems. Several major labs were racing to build the first working device. Most dismissed ruby as a lasing medium. Maiman, working on a budget of $50,000, proved them wrong. The ruby laser worked not because of institutional backing but because one engineer refused to accept the consensus.

diagram of a ruby laser from llnl document "laser programs, the first 25 years." source: wikimedia commons

When Maiman announced his result, the response was skepticism followed by a scramble. Within months, other labs replicated and extended the work. Within years, lasers were being used in surgery, telecommunications, manufacturing, and scientific research. The technology became so pervasive that it is now embedded in nearly every domain of modern life: fiber optics, barcode scanners, eye surgery, precision measurement, data storage.

Maiman's laser was a solution looking for a problem. At the time of its invention, no one knew exactly what it would be used for. It was called "a solution in search of a problem." That turned out to be its greatest strength. A tool with no predetermined purpose becomes a tool for everything. Coherent light, it turned out, was a universal design material.