What type of light is produced by a laser?

Laser light is characterized by its coherent nature, meaning that the light waves are in phase both temporally and spatially. This coherence results in a narrow beam of light that can travel over long distances with minimal spreading. In lasers, the process of stimulated emission causes the emitted photons to have the same wavelength and phase, contributing to the uniqueness of laser light.

In contrast, diffuse light is emitted from sources such as light bulbs or the sun, where the light waves are emitted in various directions and do not maintain a consistent phase relationship. Incoherent light, like that produced by typical sources, consists of multiple wavelengths and phases without synchronization. Scattered light arises when light interacts with particles, causing it to spread in different directions, which also lacks the coherence found in laser light.

Understanding these characteristics highlights why laser light is distinct and why it is used in applications requiring precise, directed light beams, such as in surgical procedures, communications, and optical devices.