Lasers produce a narrow beam of light in which all of the light waves have very similar wavelengths. The laser's light waves travel together with their peaks all lined up, or in phase. This is why laser beams are very narrow, very bright, and can be focused into a very tiny spot.

How does a laser function?

laser, a device that stimulates atoms or molecules to emit light at particular wavelengths and amplifies that light, typically producing a very narrow beam of radiation. The emission generally covers an extremely limited range of visible, infrared, or ultraviolet wavelengths.

Do lasers go on forever?

A: The light from a laser in space would continue on forever unless it hit something. However, if you were far enough away, you wouldn't be able to detect the light. ... If you go far enough away, the light will eventually spread out far enough to be undetectable.