Fred P. Seeber, Ph.D., Camden County College, Box 200, Little Gloucester Road, Blackwood, NJ 08012. Although Albert Einstein in 1916 studied the action of electrons in atoms and theorized that light of a specific wavelength would stimulate electrons to emit photons of the same wavelength, it wasn't until 1960 that Theodore H. Maiman built the first laser. Basically, a laser is a device that employs the principles of modern physics to produce a very narrow, intense beam of light. The light in this beam is different from ordinary light like that of the sun or from electric light bulbs. It has special properties that make it useful for many purposes.
Laser light is made up of only one color of light concentrated into a narrow band of frequencies.
This property is called monochromaticity. A third characteristic is coherence. The waves of a laser travel in step with one another like the members of a marching band. The force created by all the members putting a foot down at the same time is much stronger than random steps at different times. Likewise, the force of the signal or pulse from the coherent beam of light is more powerful than that of any single wave.