Exhibit Sections

Since ancient times, people believed that rays of light carry grand and mysterious powers. Interest in radiation redoubled around the start of the 20th century with the discovery of radio, X-rays and radioactivity. A whole spectrum of radiation opened up, with wavelengths longer or shorter than light (see sidebar). What amazing new uses might be discovered for use in medicine, communications, scientific research — or warfare?... more...

Already in the 1930s scientists could have built a laser. They had the optical techniques and theoretical knowledge — but nothing pushed these together. The push came around 1950 from an unexpected direction. Short-wavelength rays could make a cluster of atoms vibrate in revealing ways (a technique called microwave spectroscopy). Radar equipment left over from World War II was reworked to provide the radiation... more...

Physicists had been working for generations toward controlling ever shorter wavelengths. After radio (meters) and radar (centimeters, then millimeters), the logical next step would be far-infrared waves. Masers had been modestly useful, more for scientific research than for military or industrial applications. Only a few scientists thought an infrared maser might be important and pondered how to make one... more...

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... more...

Fifty years after the first laser, there are few people in modern society who have not been affected by the invention.

Revolutionizing Communications. In the 1980’s telecommunication systems relied on bulky copper cable, which was at the limits of its signal-carrying... more...