List of light sources

This article lists sources of light, the visible part of the electromagnetic spectrum. It focuses on primary light sources (which emit light) rather than secondary light sources (which reflect or transmit light). Primary light sources produce photons from another energy source, such as heat, chemical reactions, or conversion of mass or a different frequency of electromagnetic radiation, and include light bulbs and stars like the Sun. Secondary light sources (e.g., cat eyes, retroreflectors) do not actually produce the light that comes from them.

A common and fundamental means of classifying primary light sources is on the basis of the mechanism(s) of light emission. Light is generated when an electric charge undergoes acceleration, typically through incandescence or luminescence. Light from real light sources (e.g., stars, gas mantles, limelight, phosphor-based white LEDs) is often from a combination of mechanisms. Real light sources can in turn be categorised as anthropic ("artificial") or naturally occurring.