Modern Communication (Spanish version, 2003)

Summary: Many new technologies rely on lasers and fiber optics. The principle behind a laser lies embedded in the heart of quantum mechanics. Einstein built on the theory of quantum mechanics to explain the photoelectric effect in 1905 and showed that electrons could absorb and emit the energy of photons. In 1917, he went on to discover that this emission could be “focused” so that it occurs at a single frequency. Scientists applied this principle in the mid-1950s to visible light and used the term laser for this device. However, they could not produce a steady laser light, which was necessary for practical applications. Research on semiconductors led to the development of semiconductor lasers. By the late 1960s, researchers had devised a method to operate lasers continuously at room temperatures using layers of semiconductors. Now they needed to find a method to transmit light across large distances. Researchers continued exploring techniques to allow glass fibers to carry light without too much loss. Meanwhile, scientists continued improving laser technology and by the late 1970s, commercial use of fiber-optic systems had begun.