When were lasers created?
The idea of using visible light came around in the late '50's with the first patent attempt in 1958. The first working laser was made in 1960. It was based on an earlier invention called the MASER that used microwaves. The first thought about using infrared but then settled on visible light.
Because it used visible light, the first patent used the term "optical MASER" instead of "LASER". The term LASER came from a paper in 1959 that spoke of the concept.
LASER stands for: Light Amplification by Stimulated Emission of Radiation. (for MASER, replace "light" with "microwave")
All tunable LASERs are LASERS, however not all LASERS are tunable. In a tunable laser the lasing medium, which is typically a gas, dye or crystal, can be altered to produce slightly different frequencies, thus allowing the laser to be 'tuned' or frequency changed where most LASERS produce a very narrow band of radiation frequencies.