That something like a laser was even possible, was proven back in 1917, when Einstein performed fundamental studies on the nature of light, discovering the principles of spontaneous and stimulated emission.



After the second world war it was quite the popular research, but it wasn't until the 16th of may 1960 Theodore Maiman, C.K. Asawa, and I.J. D’Haenens have developed the first working laser at Hughes Research Labs.

Check out this awesome laser timeline!