The theory of stimulated emission was first proved by Albert Einstein in 1916, then population inverse was discussed by V. A. Fabrikant in 1940. This led to the building of the first ammonia maser in 1954 by J. P. Gordon, H. J. Zeiger, and Charles H. Townes. In July of 1960 Theodore H. Maiman announced the generation of a pulse of coherent red light by means of a red crystal- the first laser. In 1987 Gordon Gould won a patent he had been trying to get for three years to build the first gas-discharged laser which he had conceived in 1957. In that same patent the helium-neon was included.
Light is just like radio waves in the way that it can also carry information.
The information is encoded in the beam as variations in the frequency or shape of the light wave. The good part is that since light waves have much higher frequencies they can also hold much more information. Not only is the particle the smallest light unit but it is a particle as well as a wave. Even if the light is of a single frequency that statement would also be true. A laser is useful because it produces light that is not only of essentially a single frequency but also coherent, with the light waves all moving along in unison.