Photoluminescence

Part of speech: noun

Definitions

1. The process through which certain substances convert absorbed light into emitted light is observed when they interact with photons in an excited state
2. This phenomenon describes the ability of specific materials to take in light energy and subsequently release it as visible light after being stimulated
3. The occurrence in which certain materials absorb light and then re-emit it as luminescence can be seen in various applications of physics

Etymology: Photoluminescence is a technical coinage, built plainly from two parts: "photo-", from Ancient Greek "phōs" meaning light, and "luminescence", itself from Latin "lumen", light. The first element is the Greek root that also gives English words like photograph, while the second traces back to the Latin noun for light and the suffix that forms words for a process or state of glowing. Put together, the term describes a substance that gives off its own glow after it has absorbed light. Nothing about the word is a survival from ancient times. Its parts were available to scientists from classical roots, and the compound was assembled in modern scientific English to name a specific phenomenon. The sense stayed close to its literal parts: light goes in, and light comes back out, a delay that distinguishes photoluminescence from something like a flame, which glows from heat.