ljusutsänd

Ljusutsänd is a Swedish term that translates to "light emission" or "luminescence." It describes the phenomenon where a substance emits light. This can occur through various physical processes, not solely related to heat, which distinguishes it from incandescence.

One common form of ljusutsänd is fluorescence, where a material absorbs light at one wavelength and re-emits it at a longer wavelength. Phosphorescence is similar but involves a delayed emission of light after the excitation source has been removed, often referred to as "glow-in-the-dark" effects.

Bioluminescence is another manifestation of ljusutsänd, produced by living organisms through chemical reactions. This is observed in fireflies, certain fungi, and marine life. Chemiluminescence is a related process, occurring in non-living systems, such as the reactions that power glow sticks.

Electroluminescence is light produced when an electric current passes through a material, a principle utilized in LEDs (light-emitting diodes) and OLEDs (organic light-emitting diodes). Ljusutsänd, in its broadest sense, encompasses all these mechanisms by which light is generated without requiring high temperatures. The study of ljusutsänd is crucial in fields ranging from materials science and physics to biology and technology.