In the late 1940s, Townes experimented with microwaves and in 1951 he constructed a device that could generate and amplify these microwaves. Based on Einstein’s theory, Townes gave his discovery the name “Maser” - an acronym for “microwave amplification by stimulated emission of radiation”. What was possible with microwaves, i.e. the amplification by stimulated emission of radiation, should also be feasible for infrared or conventional light, knowing that as the wavelength decreases, the cost of constructing a laser greatly increases.
However, it was a few more years before a “light amplification by stimulated emission of radiation” (laser) was created from this assumption. At this stage all materials required to build a laser were known and available. The first laser, consisting of a flash lamp, a synthetically manufactured ruby doped with chromium and a metal sleeve, was finally created in the hands of physicist Theodore Maiman in 1960. However, this discovery was initially overlooked by experts. When Maiman wanted to have his findings printed in a journal, the editors refused to accept the text - the possibility of combining coherent light beams with high colour purity seemed trivial.
Only in years to come did it become clear what was possible with laser technology, with a wide range of laser systems currently in existence. All these laser machines are based on the principle that Einstein predicted in 1917 and Theodore Maiman experimentally demonstrated in 1960.