The word laser is an acronym for Light Amplification by Stimulated Emission of Radiation. Lasers are exceptional sources of light. Dissimilar to other types of incandescent light such as a torch bulb, the laser unifies all its power into a narrow band of wavelengths. The output is monochromatic, being a single and pure colour. At its output wavelength, laser light is more intense than any other type of light. In addition, it is also greatly directional. Laser beams have been able to reach the moon, outstretched to only 1.6 kilometres across this vast distance.
The explanation for why laser light is so different, exists in the way in which it is generated. When atoms alter from high to low power levels, they discharge excess energy or photons of light in the shape of limited batches of radiation, known as quanta. When the discharge is random, it is known as spontaneous emission. However, if these photons meet with similarly energised atoms, they will be made to give off photons as well. This procedure is called stimulated emission. It has the outstanding characteristic that the second atom will emit photons at precisely the same wavelength and in exactly the same direction as the original light causing intense amplification.
Lasers are commonly in use in many areas of everyday life from rock concert light shows to life saving surgical operations.
