Lasers by Charlie Balcom

1916: Albert Einstein hypothesized that atoms could release excess energy as light under certain circumstances.

1928: Einstein's ideas caused Rudolf Walther to study stimulated emission of atoms. This research still had no practical use.

1953: The research of Walther and ideas of Einstein resulted in Charles H. Towns generating stimulated emission at microwave frequencies on "excited" ammonia molecules. He calls it a maser (microwave amplification by the stimulated emission of radiation).

Because this research was done without a practical use in mind, masers had limited application such as microwave amplifiers and atomic clocks.

Dec 1958: Towns and his brother-in-law Arthur L. Schawlow publish ideas for an "optical maser" with shorter wavelengths of infrared or visible light.

Late 1950s: Gordon Gould invents his own laser ideas and coins the word laser.

Gould speculates that lasers will become powerful enough to cut and drill through materials

May 1960: Inspired by the research of Towns, Theodore H. Maiman fires pulses from a photographer's flash lamp exciting chromium in synthetic ruby producing red pulses.

Lasers become popular because they are similar to the "heat rays" of science fiction

1950s: Aleksandr Mikhaylovich Prokhorov and Nikolay Gennadieyevich Basov also independently invent the same thing as Towns.

1964: All three scientists win Nobel Prizes for Physics

1963: Emmett Leith and Juris Upatnieks make holograms with lasers

1962: One of the first helium neon laser uses was projecting straight lines for alignment in construction.

Lasers begin to have diverse applications as a result of the boom in research and development in the late 1950s and early 1960s.

1960s: Laser pointers are used in lecture halls

Late 1980s - Early 1990s: Eye surgeons begin to use pulses from ruby lasers to weld detached retinas back together

1979: Lasers become used for CD audio players and laser printers

1969: Laser target designators guide smart bombs to their targets

Mid 1970s: Lasers become used large scale in supermarket checkouts

Key:

Green lines = Causally related

Blue lines = Chronological order

Red lines = Related to a specific event/events

Dec: 1960: Ali Javan, William Bennett Jr. and Donald Harriot build the first gas laser (helium neon laser) which fires a continuous infrared beam. The invention of helium neon lasers led to many different technologies being invented because the laser beam was visible.