A laser beam is an extremely intense narrow parallel beam of light. The word itself is derived from the words ‘light amplification by stimulated emission of radiation’.

Albert Einstein said in 1917 that it should be possible to make rays of light of the correct frequently be directed on an atom to make it release its energy in the form of light, but it was until 1958 that the right calculations were made by A.L. Schawlow and C.H. Townes to make this possible.
Schawlow and Townes’s first experiments failed, but by 1960 they had succeeded in generating the first laser beam, using a type of ruby.

Since then, the laser has been used in high-powered versions for cutting through metal, in delicate surgery such as in eye operations - and for putting on special effects at pop concerts and for street Christmas light displays!