How Laser Pointers Work

The process by which a laser works may seem complicated at first but it is actually quite simple. Lasers have certain characteristics that separate it from regular "white" light. As you may know, light from a laser travels in a straight beam that concentrates itself onto a small area.

Laser is an acronym meaning Light Amplification by Stimulated Emission of Radiation. Stimulated Emission is a process used by lasers to amplify light waves. There is a high concentration of excited atoms inside a laser. Atoms inside the lasing medium become stimulated through a pair of mirrors that reflect light. When atoms are in this excited state, photons are emitted as atoms give off their excess energy. Photons, which have a specific wavelength, are light energy.

Unlike normal flashlights, the light produced by a laser is highly coherent because it is "organized" light. When a light wave given off by one atom strikes another, the second atom emits energy in the form of light that travels in phase and in the same direction as the light from the first atom. Amplification of the first wave results in stimulated emission. As stimulated emission continually occurs, an intense beam of light is created.

Light given off by a laser is also monochromatic. This means that the light contains a specific wavelength which results in a specific color. The wavelength is determined by the amount of energy released from the atoms. Most commonly, laser pointers produce a red or green beam of light.