We have seen that white light is a mixture of many colours which can be separated. It helps to think of these colours as waves. Each different colour of light has a different length of wave. Red light has long waves. Blue light has short waves. However, the light produced by a laser is the entire same wavelength.
This means that a beam of light produced by a laser can be easily concentrated onto a tiny point. It can produce enough heat to turn a metal into a vapour! Lasers can be used as accurate cutting tools which can even cut through diamond, the hardest substance known.
Laser light and wavelength
White light from a torch can be thought of as a mixture of waves. Each wavelength represents a certain colour. The waves making up a laser beam are quite different.
Not only are all the waves the same length (colour), but they are lined up so that the tops (peaks) of the waves coincide.
The various wavelengths making up white light can be separated by a prism. We know that laser light is all of one wavelength because it cannot be separated by a prism.
Waves of laser light are all bent to the same extent by the prism since they all travel at the same speed through glass.
Beams of laser light are powerful enough to cut through metal.
Picture Credit : Google